Use explicit Go version in github actions

Author: janos

.github/workflows/go.yml

@@ -14,7 +14,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.x
+        go-version: 1.14
 
     - name: Set up env
       run: |