Update to golang 1.17 in test runners

Signed-off-by: Paulo Gomes <paulo.gomes@weave.works>

.github/workflows/build.yaml

@@ -1,5 +1,4 @@
 name: build
-
 on:
   pull_request:
   push:
@@ -15,6 +14,10 @@ jobs:
     steps:
     - name: checkout
       uses: actions/checkout@v2
+    - name: Setup Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: 1.17.x
     - name: Restore go cache
       uses: actions/cache@v1
       with:
@@ -35,6 +38,10 @@ jobs:
     steps:
     - name: checkout
       uses: actions/checkout@v2
+    - name: Setup Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: 1.17.x
     - name: Restore go cache
       uses: actions/cache@v1
       with: