update go.yml (#534)

.github/workflows/go.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       matrix:
         config:
-          - go_version: 1.17
+          - go_version: 1.15
     steps:
 
     - name: Set up Go 1.x
@@ -23,16 +23,9 @@ jobs:
         go-version: ${{ matrix.config.go_version }}
       id: go
 
-    - name: Get dependencies
-      run: |
-            go get -v -t -d ./...
-
     - name: Check out code into the Go module directory
       uses: actions/checkout@v2
 
-    - name: Install goimports
-      run: go get golang.org/x/tools/cmd/goimports
-
     - name: Test
       run: |
         diff -u <(echo -n) <(gofmt -d -s .)