Run Travis & GH actions CI side by side (#314)

Add initial GitHub workflow for running CI tests.

.github/workflows/ci.yml

@@ -0,0 +1,93 @@
+name: go-workflow
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+jobs:
+  golang-tests:
+    name: tests
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    strategy:
+      matrix:
+        go-version: ["1.15", "1.14", "1.13"]
+        go111module: ["on", "off"]
+        include:
+          # includes goflags when go111module is on
+          - go111module: "on"
+            goflags: -mod=readonly
+    env:
+      GO111MODULE: ${{ matrix.go111module }}
+      # XXX: Investigate why GOPATH is needed for Modules off
+      GOPATH: ${{ github.workspace }}
+    # Required for building with GOPATH
+    # https://github.com/mvdan/github-actions-golang#how-do-i-set-up-a-gopath-build
+    defaults:
+      run:
+        working-directory: ${{ github.workspace }}/src/github.com/getsentry/sentry-go
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          # Relative path under Github workspace
+          path: ${{ github.workspace }}/src/github.com/getsentry/sentry-go
+          # Getting all history enables using `git merge-base origin/master HEAD`
+          fetch-depth: 0
+      - uses: actions/setup-go@v2
+        with:
+          go-version: ${{ matrix.go-version}}
+      - name: Adjustments for Module mode enabled
+        if: matrix.go111module == 'on'
+        run: |
+          echo "GOFLAGS=${{ matrix.goflags }}" >> $GITHUB_ENV
+      - name: Adjustments for Module mode disabled
+        if: matrix.go111module == 'off'
+        run: |
+          # Iris does not supported in legacy GOPATH mode. We delete the source code
+          # because otherwise lint, build, and test steps would fail.
+          rm -vrf ./iris/ ./example/iris/
+          # go get is not required in Module mode
+          go get -v -t ./...
+      - name: Build
+        run: go build ./...
+      - name: Tests
+        run: |
+          go test ./...
+          go test ./... -race
+      - name: Run linting if Go Module is on
+        if: matrix.go111module == 'on'
+        run: |
+          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/v1.27.0/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.27.0
+          git fetch origin master:remotes/origin/master
+          $(go env GOPATH)/bin/golangci-lint run --new-from-rev=$(git merge-base origin/master HEAD)
+
+  golang-outside-gopath:
+    name: Module support outside GOPATH
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    env:
+      GO111MODULE: on
+      GOFLAGS: -mod=readonly
+      GOPATH: ${{ github.workspace }}
+    # Required for building with GOPATH
+    # https://github.com/mvdan/github-actions-golang#how-do-i-set-up-a-gopath-build
+    defaults:
+      run:
+        working-directory: ${{ env.GOPATH }}/src/github.com/getsentry/sentry-go
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          # Relative path under Github workspace
+          path: src/github.com/getsentry/sentry-go
+      - uses: actions/setup-go@v2
+        with:
+          go-version: 1.15
+      - name: Run tests outside of GOPATH
+        run: |
+          mv $GOPATH/src/github.com/getsentry/sentry-go ~/sentry-go
+          cd ~/sentry-go
+          export GOPATH=
+          go env GOPATH
+          go test ./...
+          go test ./... -race
+