feat: create build workflow

.github/workflows/build.yml

@@ -0,0 +1,18 @@
+name: Clojure CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install dependencies
+        run: lein deps
+      - name: Generate Jars
+        run: lein uberjar