chore: add github action and badges

.github/workflows/test-actions.yml

@@ -0,0 +1,38 @@
+name: Test
+
+on: [push, pull_request]
+
+jobs:
+  Test:
+    runs-on: ubuntu-latest
+
+    container:
+      image: mikaak/elixir:1.13-alpine
+      env:
+        MIX_ENV: test
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install Rebar & Hex
+        run: mix local.hex --force --if-missing && mix local.rebar --force --if-missing
+
+      - name: Install Tar
+        run: apk add --no-cache tar
+
+      - name: Cache Deps & Build
+        uses: actions/cache@v2
+        with:
+          key: ${{github.ref}}-deps-build-cache
+          path: |
+            ./deps
+            ./_build
+            !._build/dev/lib/error_message/
+      - name: Install Dependencies
+        run: mix deps.get
+
+      - name: Compile Project
+        run: mix compile
+
+      - name: Run Tests
+        run: mix test

README.md

@@ -1,5 +1,5 @@
 ## PrometheusTelemetry
-
+[![Test](https://github.com/theblitzapp/prometheus_telemetry_elixir/actions/workflows/test-actions.yml/badge.svg)](https://github.com/theblitzapp/prometheus_telemetry_elixir/actions/workflows/test-actions.yml)
 [![Hex version badge](https://img.shields.io/hexpm/v/prometheus_telemetry.svg)](https://hex.pm/packages/prometheus_telemetry)
 
 PrometheusTelemetry is the plumbing for Telemetry.Metrics and allows the
@@ -58,8 +58,8 @@ children = [
   {PrometheusTelemetry,
     exporter: [enabled?: true],
     metrics: [
-      PrometheusTelemetry.Metrics.Ecto.metrics(), 
-      PrometheusTelemetry.Metrics.Phoenix.metrics(), 
+      PrometheusTelemetry.Metrics.Ecto.metrics(),
+      PrometheusTelemetry.Metrics.Phoenix.metrics(),
       PrometheusTelemetry.Metrics.GraphQL.metrics(),
       PrometheusTelemetry.Metrics.VM.metrics()
     ]