Added GH Action

* Provided base GitHub Actions
* Updated 'README': added GH Badges

.github/workflows/main.yml

@@ -0,0 +1,31 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+    branches: [ $default-branch ]
+  release:
+    types:
+      - created
+
+jobs:
+  test:
+    name: CI
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        otp: [22.3.4.16, 23.0.4, 23.1.5.0, 23.2.7.0]
+    container:
+      image: erlang:${{ matrix.otp }}-alpine
+    steps:
+    - name: Prepare
+      run: |
+           apk update
+           apk --no-cache upgrade
+           apk --no-cache add gcc git libc-dev libc-utils libgcc linux-headers make bash
+    - uses: actions/checkout@v2
+    - name: Build
+      run: rebar3 compile
+    - name: Run tests
+      run: |
+           rebar3 ct