build: refactor circleci script to github actions (celo-org#167)

* build: refactor circleci script to github actions

* build: check licenses no longer needed

* build: add name to workflow

* refactor: update script

* test: test that ci fails

* test: check that test fails

* test: workflow works as expected

.github/workflows/ci.yml

@@ -0,0 +1,41 @@
+name: "CI"
+
+on:
+  workflow_dispatch:
+  pull_request:
+    branches:
+      - "main"
+      - "feature/**"
+  push:
+    branches:
+      - "main"
+
+jobs:
+  ci:
+    name: Build & Test
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: "Check out the repo"
+        uses: "actions/checkout@v3"
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version: 12
+
+      - name: Install dependencies
+        run: "yarn install --immutable"
+
+      - name: Build packages
+        run: yarn build
+
+      - name: Run lint checks
+        run: |
+          yarn run prettify:diff
+          yarn run lint
+          yarn run lint:tests
+
+      - name: Run tests
+        run: yarn run test --maxWorkers 2
+