diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..6d73f90
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,103 @@
+#
+# CI build that assembles artifacts and runs tests.
+# If validation is successful this workflow releases from the main dev branch.
+#
+# - skipping CI: add [skip ci] to the commit message
+# - skipping release: add [skip release] to the commit message
+#
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+    tags-ignore:
+      - v* # release tags are automatically generated after a successful CI build, no need to run CI against them
+  pull_request:
+    branches:
+      - master
+
+jobs:
+
+  #
+  # SINGLE-JOB
+  #
+  verify:
+    runs-on:  ubuntu-latest
+
+    steps:
+
+      - name: 1. Check out code
+        uses: actions/checkout@v2 # https://github.com/actions/checkout
+
+      - name: 2. Set up Java 8
+        uses: actions/setup-java@v1 # https://github.com/actions/setup-java
+        with:
+          java-version: 8
+
+      - name: 3. Validate Gradle wrapper
+        uses: gradle/wrapper-validation-action@v1 # https://github.com/gradle/wrapper-validation-action
+
+#      need change in build
+#
+#      - name: 4. Build and check reproducibility of artifacts
+#        run: ./check_reproducibility.sh
+
+  #
+  # Main build job
+  #
+  build:
+    needs: [verify]
+    runs-on:  ${{ matrix.os }}
+    if: "! contains(toJSON(github.event.commits.*.message), '[skip ci]')"
+
+    # Definition of the build matrix
+    strategy:
+      matrix:
+        java: [8, 11, 15]
+        os: [ ubuntu-latest, windows-latest, macOS-latest ]
+
+    steps:
+
+    - name: 1. Check out code
+      uses: actions/checkout@v2 # https://github.com/actions/checkout
+
+    - name: 2. Set up Java ${{ matrix.java }}
+      uses: actions/setup-java@v1 # https://github.com/actions/setup-java
+      with:
+        java-version: ${{ matrix.java }}
+
+    - name: 3. Build on ${{ matrix.os }} with Java ${{ matrix.java }}
+      run: ./gradlew build idea
+
+  #
+  # Release job, only for pushes to the main development branch
+  #
+
+# will be activated / implemented after shipkit upgrade
+
+#  release:
+#    runs-on: ubuntu-latest
+#    needs: [build, verify] # build job must pass before we can release
+#
+#    if: github.event_name == 'push'
+#        && github.ref == 'refs/heads/release/3.x'
+#        && !contains(toJSON(github.event.commits.*.message), '[skip release]')
+#
+#    steps:
+#
+#    - name: Check out code
+#      uses: actions/checkout@v2 # https://github.com/actions/checkout
+#      with:
+#        fetch-depth: '0' # https://github.com/shipkit/shipkit-changelog#fetch-depth-on-ci
+#
+#    - name: Set up Java 8
+#      uses: actions/setup-java@v1
+#      with:
+#        java-version: 8
+#
+#    - name: Build and publish
+#      run: ./gradlew bintrayUpload githubRelease --scan
+#      env:
+#        GH_WRITE_TOKEN: ${{secrets.GH_WRITE_TOKEN}}
+#        BINTRAY_API_KEY: ${{secrets.BINTRAY_API_KEY}}
diff --git a/check_reproducibility.sh b/check_reproducibility.sh
new file mode 100755
index 0000000..d4aab96
--- /dev/null
+++ b/check_reproducibility.sh
@@ -0,0 +1,26 @@
+#!/bin/bash -e
+
+# This script is taken from https://github.com/junit-team/junit5/pull/2217
+
+rm -rf checksums/
+mkdir checksums/
+
+export SOURCE_DATE_EPOCH=$(date +%s)
+
+function calculate_checksums() {
+    OUTPUT=checksums/$1
+
+    ./gradlew --no-build-cache clean assemble
+
+    find ./build -name '*.jar' \
+        | grep '/build/libs/' \
+        | grep --invert-match 'javadoc' \
+        | sort \
+        | xargs sha256sum > ${OUTPUT}
+}
+
+
+calculate_checksums checksums-1.txt
+calculate_checksums checksums-2.txt
+
+diff checksums/checksums-1.txt checksums/checksums-2.txt
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 1948b90..e708b1c 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 8174453..4d9ca16 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionSha256Sum=3239b5ed86c3838a37d983ac100573f64c1f3fd8e1eb6c89fa5f9529b5ec091d
 distributionUrl=https\://services.gradle.org/distributions/gradle-6.7.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
index cccdd3d..4f906e0 100755
--- a/gradlew
+++ b/gradlew
@@ -1,5 +1,21 @@
 #!/usr/bin/env sh
 
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
 ##############################################################################
 ##
 ##  Gradle start up script for UN*X
@@ -28,7 +44,7 @@ APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
@@ -66,6 +82,7 @@ esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
+
 # Determine the Java command to use to start the JVM.
 if [ -n "$JAVA_HOME" ] ; then
     if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
@@ -109,10 +126,11 @@ if $darwin; then
     GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
 fi
 
-# For Cygwin, switch paths to Windows format before running java
-if $cygwin ; then
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
     APP_HOME=`cygpath --path --mixed "$APP_HOME"`
     CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+
     JAVACMD=`cygpath --unix "$JAVACMD"`
 
     # We build the pattern for arguments to be converted via cygpath
@@ -138,19 +156,19 @@ if $cygwin ; then
         else
             eval `echo args$i`="\"$arg\""
         fi
-        i=$((i+1))
+        i=`expr $i + 1`
     done
     case $i in
-        (0) set -- ;;
-        (1) set -- "$args0" ;;
-        (2) set -- "$args0" "$args1" ;;
-        (3) set -- "$args0" "$args1" "$args2" ;;
-        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
     esac
 fi
 
@@ -159,14 +177,9 @@ save () {
     for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
     echo " "
 }
-APP_ARGS=$(save "$@")
+APP_ARGS=`save "$@"`
 
 # Collect all arguments for the java command, following the shell quoting and substitution rules
 eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
 
-# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
-if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
-  cd "$(dirname "$0")"
-fi
-
 exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
index f955316..107acd3 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -1,3 +1,19 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
 @if "%DEBUG%" == "" @echo off
 @rem ##########################################################################
 @rem
@@ -13,15 +29,18 @@ if "%DIRNAME%" == "" set DIRNAME=.
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
 
 @rem Find java.exe
 if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto init
+if "%ERRORLEVEL%" == "0" goto execute
 
 echo.
 echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
@@ -35,7 +54,7 @@ goto fail
 set JAVA_HOME=%JAVA_HOME:"=%
 set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
-if exist "%JAVA_EXE%" goto init
+if exist "%JAVA_EXE%" goto execute
 
 echo.
 echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
@@ -45,28 +64,14 @@ echo location of your Java installation.
 
 goto fail
 
-:init
-@rem Get command-line arguments, handling Windows variants
-
-if not "%OS%" == "Windows_NT" goto win9xME_args
-
-:win9xME_args
-@rem Slurp the command line arguments.
-set CMD_LINE_ARGS=
-set _SKIP=2
-
-:win9xME_args_slurp
-if "x%~1" == "x" goto execute
-
-set CMD_LINE_ARGS=%*
-
 :execute
 @rem Setup the command line
 
 set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
+
 @rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
 
 :end
 @rem End local scope for the variables with windows NT shell