Use Go 1.16 in CI and goreleaser builds (#472)

Newest version of goreleaser seems to require Go 1.16: https://twitter.com/caarlos0/status/1362016990748151812

And since src-cli is rather small and works with Go 1.16, why not?

Author: mrnugget

.github/workflows/go-ci.yml

@@ -7,7 +7,7 @@ jobs:
   go-test:
     strategy:
       matrix:
-        go-version: [1.14.x, 1.15.x]
+        go-version: [1.15.x, 1.16.x]
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:

.github/workflows/goreleaser-check.yml

@@ -15,7 +15,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.15
+          go-version: 1.16
       - name: Check GoReleaser config
         uses: goreleaser/goreleaser-action@v2
         with:

.github/workflows/goreleaser.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.15
+          go-version: 1.16
       - run: go get -d -t ./...
       - run: go test -i ./...
       - run: go test -race -v ./...

Dockerfile

@@ -4,7 +4,7 @@
 #
 # Nothing fancy here: we copy in the source code and build on the Alpine Go
 # image. Refer to .dockerignore to get a sense of what we're not going to copy.
-FROM golang:1.15-alpine@sha256:86a9ac87a3317d2635b817493a9df24ad6fff38b8bcee4a72ce511305b897646 as builder
+FROM golang:1.16-alpine@sha256:a23dc7ff6fb9b0fa3017035404b0abea819801b6bf0eb08667b3a549d3d17dbd as builder
 
 COPY . /src
 WORKDIR /src