Switch mesh to use GitHub Actions instead of Travis for CI.

PiperOrigin-RevId: 317700292

.github/workflows/build.yml

@@ -0,0 +1,37 @@
+name: build
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.x'
+    - name: Install dependencies
+      run: |
+        pip install tf-nightly mock pytest
+        pip install -e .[auto_mtf,transformer]
+    - name: Test with pytest
+      run: pytest
+    # The below step just reports the success or failure of tests as a "commit status".
+    # This is needed for copybara integration.
+    - name: Report success or failure as github status
+      if: always()
+      shell: bash
+      run: |
+        status="${{ job.status }}"
+        lowercase_status=$(echo $status | tr '[:upper:]' '[:lower:]')
+        curl -sS --request POST \
+        --url https://api.github.com/repos/${{ github.repository }}/statuses/${{ github.sha }} \
+        --header 'authorization: Bearer ${{ secrets.GITHUB_TOKEN }}' \
+        --header 'content-type: application/json' \
+        --data '{
+            "state": "'$lowercase_status'",
+            "target_url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+            "description": "'$status'",
+            "context": "github-actions/build"
+            }'

README.md

@@ -7,7 +7,7 @@ Issues](https://img.shields.io/github/issues/tensorflow/mesh.svg)](https://githu
 [![Contributions
 welcome](https://img.shields.io/badge/contributions-welcome-brightgreen.svg)](CONTRIBUTING.md)
 [![License](https://img.shields.io/badge/License-Apache%202.0-brightgreen.svg)](https://opensource.org/licenses/Apache-2.0)
-[![Travis](https://img.shields.io/travis/tensorflow/mesh.svg)](https://travis-ci.org/tensorflow/mesh)
+[![Build Status](https://github.com/tensorflow/mesh/workflows/build/badge.svg)](https://github.com/tensorflow/mesh/actions?query=workflow%3Abuild)
 
 
 # Introduction