Use github actions for OSX (#164)

* Use github actions for OSX

* Remove .travis.yml

Author: Justin Boswell

.github/workflows/mac-osx-ci.yml

@@ -0,0 +1,23 @@
+name: CI
+
+on: [push]
+
+jobs:
+  OSX:
+
+    runs-on: macOS-10.14
+
+    steps:
+    - name: Checkout Source
+      uses: actions/checkout@v1
+    
+    - name: Install Dependencies
+      run: |
+        brew install llvm
+        export PATH=$(brew --prefix llvm)/bin:$PATH
+    
+    - name: Build and test
+      run: |
+        export CODEBUILD_SRC_DIR=$(pwd)
+        python3 -c "from urllib.request import urlretrieve; urlretrieve('https://raw.githubusercontent.com/awslabs/aws-c-common/master/codebuild/builder.py', 'builder.py')"
+        python3 builder.py build macos-default-default-macos-x64