update to Go 1.19

As our official policy is to support the latest version of Go, we
upgrade our CI and release workflows to version 1.19, which was
recently released.

We also drop support for versions older than 1.18 as they are
not supported by upstream Go.

.github/workflows/ci.yml

@@ -7,7 +7,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-20.04, macos-latest]
-        go: ['1.18.x']
+        go: ['1.19.x']
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v1
@@ -38,7 +38,7 @@ jobs:
     name: Build with specific Go
     strategy:
       matrix:
-        go: ['1.17.x']
+        go: ['1.18.x']
     runs-on: ubuntu-20.04
     steps:
     - uses: actions/checkout@v1
@@ -54,7 +54,7 @@ jobs:
     - uses: actions/setup-ruby@v1
     - uses: actions/setup-go@v2
       with:
-        go-version: '1.18.x'
+        go-version: '1.19.x'
     - run: mkdir -p "$HOME/go/bin"
       shell: bash
     - run: set GOPATH=%HOME%\go

.github/workflows/release.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: windows-latest
     strategy:
       matrix:
-        go: ['1.18.x']
+        go: ['1.19.x']
     steps:
     - uses: actions/checkout@v1
     - uses: actions/setup-ruby@v1
@@ -61,7 +61,7 @@ jobs:
     runs-on: macos-latest
     strategy:
       matrix:
-        go: ['1.18.x']
+        go: ['1.19.x']
     steps:
     - uses: actions/checkout@v1
     - uses: actions/setup-ruby@v1
@@ -97,7 +97,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        go: ['1.18.x']
+        go: ['1.19.x']
     steps:
     - uses: actions/checkout@v1
     - uses: actions/setup-ruby@v1