CI: Create GitHub Actions unit test workflow (#15223)

* Create GitHub Actions unit test workflow

* Create GitHub Actions unit test workflow - checkout submodules

* Create GitHub Actions unit test workflow - update job name

* Develop branch.

* Update .github/workflows/unit_test.yml

Co-authored-by: Joel Challis <git@zvecr.com>

* Update .github/workflows/unit_test.yml

Co-authored-by: Joel Challis <git@zvecr.com>

* builddefs

Co-authored-by: zvecr <git@zvecr.com>

.github/workflows/cli.yml

@@ -4,7 +4,7 @@ on:
   push:
     branches:
     - master
-    - future
+    - develop
   pull_request:
     paths:
     - 'lib/python/**'

.github/workflows/unit_test.yml

@@ -0,0 +1,30 @@
+name: Unit Tests
+
+on:
+  push:
+    branches:
+    - master
+    - develop
+  pull_request:
+    paths:
+    - 'builddefs/**'
+    - 'quantum/**'
+    - 'platforms/**'
+    - 'tmk_core/**'
+    - 'tests/**'
+    - '*.mk'
+    - 'Makefile'
+    - '.github/workflows/unit_test.yml'
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    container: qmkfm/base_container
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: recursive
+    - name: Run tests
+      run: make test:all