Bumping up CI to go1.17 and enabling CI for PRs.

.github/workflows/main.yml

@@ -1,6 +1,12 @@
 name: CI
 
-on: [push]
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
 
 jobs:
   build:
@@ -12,7 +18,7 @@ jobs:
     - name: Setup Go for use with actions
       uses: actions/setup-go@v2
       with:
-        go-version: 1.15
+        go-version: 1.17
     - name: Install goimports
       run: go get golang.org/x/tools/cmd/goimports
     - name: Set env with list of directories in repo containin go code