add test prereq and push branches

Author: tannewt

.github/workflows/build.yml

@@ -1,16 +1,25 @@
 name: Build CI
 
-on: [push, pull_request, release]
-
-push:
-  branches:
-  - master
-  - github-ci
+on:
+  push:
+    branches:
+    - master
+    - github-ci
+  pull_request:
+  release:
 
 jobs:
-  build:
+  test:
+    runs-on: ubuntu-16.04
+    steps:
+    - name: Set up Python 3.5
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.5
 
+  build:
     runs-on: ubuntu-16.04
+    needs: test
     strategy:
       matrix:
         board: ["metro_m0_express", "metro_m4_express"]