chore: allow WITH_RUST=false to disable the rust build

also update travis to (hopefully) latest pypy

Closes: #1046

.travis.yml

@@ -11,13 +11,13 @@ matrix:
   include:
     - python: 2.7
       env: TOXENV=py27 DDB=true CODECOV=true
-    - python: pypy-5.7.1
+    - python: pypy
       env: TOXENV=pypy DDB=true CODECOV=true
-    - env: TOXENV=flake8
+    - env: TOXENV=flake8 WITH_RUST=false
     - python: 3.6
-      env: TOXENV=py36-mypy
+      env: TOXENV=py36-mypy WITH_RUST=false
   allow_failures:
-    - env: TOXENV=py36-mypy
+    - env: TOXENV=py36-mypy WITH_RUST=false
 
 before_install:
 # https://github.com/travis-ci/travis-ci/issues/7940
@@ -26,7 +26,7 @@ before_install:
 install:
 - ${DDB:+make ddb}
 - pip install tox ${CODECOV:+codecov}
-- curl https://sh.rustup.rs | sh -s -- -y
+- if [ ${WITH_RUST:-true} != "false" ]; then curl https://sh.rustup.rs | sh -s -- -y || travis_terminate 1; fi
 - export PATH=$PATH:$HOME/.cargo/bin
 script:
 - tox -- ${CODECOV:+--with-coverage --cover-xml --cover-package=autopush}

setup.py

@@ -10,9 +10,19 @@
 with io.open(os.path.join(here, 'CHANGELOG.md'), encoding='utf8') as f:
     CHANGES = f.read()
 
+WITH_RUST = os.environ.get('WITH_RUST', 'true').lower() not in ('false', '0')
+
 extra_options = {
     "packages": find_packages(),
 }
+if WITH_RUST:
+    extra_options.update(
+        setup_requires=['snaek'],
+        install_requires=['snaek'],
+        snaek_rust_modules=[
+            ('autopush_rs._native', 'autopush_rs/'),
+        ],
+    )
 
 
 setup(name="AutoPush",
@@ -45,10 +55,5 @@
       [nose.plugins]
       object-tracker = autopush.noseplugin:ObjectTracker
       """,
-      setup_requires=['snaek'],
-      install_requires=['snaek'],
-      snaek_rust_modules=[
-          ('autopush_rs._native', 'autopush_rs/'),
-      ],
       **extra_options
       )

tox.ini

@@ -16,7 +16,7 @@ setenv = with_gmp=no
 
 [testenv:flake8]
 commands = flake8 autopush
-deps += flake8
+deps = flake8
 
 [testenv:py36-mypy]
 commands = mypy autopush