Added CI

- Added GitHub workflow 'PK-Rust Tests'

.github/workflows/ci.yml

@@ -0,0 +1,20 @@
+on:
+  push:
+    branches:
+      - main
+
+name: CI
+
+jobs:
+  build_and_test:
+    name: PK-Rust Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+      - uses: actions-rs/cargo@v1
+        with:
+          command: test
+        #   args: --release --all-features