Switch from Travis to GitHub Actions (#940)

We're deprecating use of Travis for our OSS projects, so switch to
GitHub Actions for it.

Unfortunately, this required dropping tests we had against ppc64le
because [GitHub Workflows doesn't support it][1].

  [1]: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#github-hosted-runners

.github/workflows/go.yml

@@ -0,0 +1,52 @@
+name: Go
+
+on:
+  push:
+    branches: ['*']
+    tags: ['v*']
+  pull_request:
+    branches: ['*']
+
+jobs:
+
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go: ["1.15.x", "1.16.x"]
+        include:
+        - go: 1.16.x
+          latest: true
+
+    steps:
+    - name: Setup Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: ${{ matrix.go }}
+
+    - name: Checkout code
+      uses: actions/checkout@v2
+
+    - name: Load cached dependencies
+      uses: actions/cache@v1
+      with:
+        path: ~/go/pkg/mod
+        key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+        restore-keys: |
+          ${{ runner.os }}-go-
+
+    - name: Download Dependencies
+      run: go mod download
+
+    - name: Lint
+      if: matrix.latest
+      run: make lint
+
+    - name: Test
+      run: make cover
+
+    - name: Upload coverage to codecov.io
+      uses: codecov/codecov-action@v1
+
+    - name: Benchmark
+      run: make bench

README.md

@@ -125,8 +125,8 @@ pinned in the [benchmarks/go.mod][] file. [↩](#anchor-versions)
 
 [doc-img]: https://pkg.go.dev/badge/go.uber.org/zap
 [doc]: https://pkg.go.dev/go.uber.org/zap
-[ci-img]: https://travis-ci.com/uber-go/zap.svg?branch=master
-[ci]: https://travis-ci.com/uber-go/zap
+[ci-img]: https://github.com/uber-go/zap/actions/workflows/go.yml/badge.svg
+[ci]: https://github.com/uber-go/zap/actions/workflows/go.yml
 [cov-img]: https://codecov.io/gh/uber-go/zap/branch/master/graph/badge.svg
 [cov]: https://codecov.io/gh/uber-go/zap
 [benchmarking suite]: https://github.com/uber-go/zap/tree/master/benchmarks