ci: add changelog check (#1112)

Author: mtrezza

.github/workflows/ci.yml

@@ -9,7 +9,16 @@ on:
     branches:
       - '**'
 jobs:
-  build:
+  check-changelog:
+    name: Changelog
+    timeout-minutes: 5
+    runs-on: ubuntu-18.04
+    steps:
+    - uses: actions/checkout@v2
+    - uses: dangoslen/changelog-enforcer@v2
+  check-build:
+    name: Gradle Build
+    timeout-minutes: 5
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2