Add Scala CLA

.github/workflows/cla.yml

@@ -0,0 +1,8 @@
+name: Scala CLA
+on: [pull_request]
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - run: ./project/scripts/check-cla.sh

CONTRIBUTING.md

@@ -4,6 +4,8 @@ This document explains the developer workflow for making changes to the
 [Scala Syntax (official) extension](https://marketplace.visualstudio.com/items?itemName=scala-lang.scala)
 for Visual Studio Code.
 
+To contribute, make sure you have signed the [Scala CLA](http://typesafe.com/contribute/cla/scala), if not, please sign it.
+
 ## Prerequisites
 
 Make sure you have the following binaries installed:

project/scripts/check-cla.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+set -eux
+
+AUTHOR=$GITHUB_ACTOR
+echo "Pull request submitted by $AUTHOR";
+signed=$(curl -s https://www.lightbend.com/contribute/cla/scala/check/$AUTHOR | jq -r ".signed");
+if [ "$signed" = "true" ] ; then
+  echo "CLA check for $AUTHOR successful";
+else
+  echo "CLA check for $AUTHOR failed";
+  echo "Please sign the Scala CLA to contribute to the Scala compiler.";
+  echo "Go to https://www.lightbend.com/contribute/cla/scala and then";
+  echo "comment on the pull request to ask for a new check.";
+  echo "";
+  echo "Check if CLA is signed: https://www.lightbend.com/contribute/cla/scala/check/$AUTHOR";
+  exit 1;
+fi;