Bump go versions (#137)

Author: fgsch

.github/workflows/main.yml

@@ -20,7 +20,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        go: ['1.16.x', '1.17.x']
+        go: ['1.17.x', '1.18.x']
     steps:
     - uses: actions/checkout@v2
 
@@ -80,7 +80,7 @@ jobs:
     - run: python ci/download-wasmtime.py
     - uses: actions/setup-go@v2
       with:
-        go-version: '1.17'
+        go-version: '1.18'
     - run: go test -coverprofile cover.out ./...
     - run: go tool cover -html=cover.out -o coverage.html
     - uses: actions/upload-artifact@v1
@@ -94,7 +94,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: actions/setup-go@v2
       with:
-        go-version: '1.17'
+        go-version: '1.18'
     # https://stackoverflow.com/questions/42510140/check-format-for-continous-integration
     - run: "diff -u <(echo -n) <(gofmt -d ./)"