transition to functional GitHub Actions CI (digitalocean#176)

* transition to functional GitHub Actions CI

Travis CI has historically waffled back and forth about how it feels
about a free-tier plan for open source projects. It's a rollercoaster
that I personally don't ever want to ride again.

Furthermore, go-qemu's CI seems to be down in the doldrums, so replace
it with a simple GitHub Actions workflow.

* Replace Travis CI badge with GHA badge

* temporarily disable license check

Author: connorkuehl

.github/workflows/goqemu.yml

@@ -0,0 +1,56 @@
+name: go-qemu
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        # track upstream Go's currently supported stable versions.
+        gorelease: ['1.17', '1.18']
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+          key: go-${{ matrix.gorelease }}-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            go-${{ matrix.gorelease }}
+
+      - uses: actions/setup-go@v3
+        with:
+          go-version: ${{ matrix.gorelease }}
+
+      - name: build/go-${{ matrix.gorelease }}
+        run: go build -v ./...
+
+      - name: test/go-${{ matrix.gorelease }}
+        run: go test -v ./...
+
+# disabled for now, seeing as it is complaining about things that seem like
+# non-issues and that are helpful.
+#
+# I.e., it dislikes assert helpers:
+#
+#   qmp/socket_test.go:238:4: call to (*T).Fatalf from a non-test goroutine
+#     - name: vet
+#       run: go vet ./...
+
+# disabled for now, is incompatible with anything that doesn't have 2016 as
+# the year. Might need fixing if we want to keep this.
+#
+#     - name: check license
+#       run: ./scripts/licensecheck.sh
+
+      - name: check code generation
+        run: |
+          go install golang.org/x/tools/cmd/stringer@latest
+          ./scripts/codegeneration.sh
+
+      - name: golint
+        run: |
+          go install golang.org/x/lint/golint@latest
+          ./scripts/golint.sh

.travis.yml

@@ -1,4 +1,4 @@
-go-qemu [![GoDoc](http://godoc.org/github.com/digitalocean/go-qemu?status.svg)](http://godoc.org/github.com/digitalocean/go-qemu) [![Build Status](https://travis-ci.org/digitalocean/go-qemu.svg?branch=master)](https://travis-ci.org/digitalocean/go-qemu) [![Report Card](https://goreportcard.com/badge/github.com/digitalocean/go-qemu)](https://goreportcard.com/report/github.com/digitalocean/go-qemu)
+go-qemu [![GoDoc](http://godoc.org/github.com/digitalocean/go-qemu?status.svg)](http://godoc.org/github.com/digitalocean/go-qemu) ![Build Status](https://github.com/digitalocean/go-qemu/actions/workflows/goqemu.yml/badge.svg?branch=master) [![Report Card](https://goreportcard.com/badge/github.com/digitalocean/go-qemu)](https://goreportcard.com/report/github.com/digitalocean/go-qemu)
 =======
 
 `go-qemu` is a collection of Go packages for interacting with running QEMU