Define GitHub Actions workflow for Core module (#9)

This is an initial implementation of the CI process to check the
formatting, build contracts, test them, and run deployment with the
local hardhat network.

.github/workflows/core.yaml

@@ -0,0 +1,109 @@
+name: Core
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - "core/**"
+  pull_request:
+
+defaults:
+  run:
+    working-directory: ./core
+
+jobs:
+  core-format:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Node
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: "core/.nvmrc"
+          cache: "yarn"
+          cache-dependency-path: "core/yarn.lock"
+
+      - name: Install Dependencies
+        run: yarn install --prefer-offline --frozen-lockfile
+
+      - name: Format
+        run: yarn format
+
+  core-build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Node
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: "core/.nvmrc"
+          cache: "yarn"
+          cache-dependency-path: "core/yarn.lock"
+
+      - name: Install Dependencies
+        run: yarn install --prefer-offline --frozen-lockfile
+
+      - name: Build
+        run: yarn build
+
+      - name: Upload Build Artifacts
+        uses: actions/upload-artifact@v3
+        with:
+          name: core-build
+          path: |
+            core/build/
+            core/typechain/
+          if-no-files-found: error
+
+  core-test:
+    needs: [core-build]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Node
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: "core/.nvmrc"
+          cache: "yarn"
+          cache-dependency-path: "core/yarn.lock"
+
+      - name: Install Dependencies
+        run: yarn install --prefer-offline --frozen-lockfile
+
+      - name: Download Build Artifacts
+        uses: actions/download-artifact@v3
+        with:
+          name: core-build
+          path: core/
+
+      - name: Test
+        run: yarn test --no-compile
+
+  core-deploy-dry-run:
+    needs: [core-build]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Node
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: "core/.nvmrc"
+          cache: "yarn"
+          cache-dependency-path: "core/yarn.lock"
+
+      - name: Install Dependencies
+        run: yarn install --prefer-offline --frozen-lockfile
+
+      - name: Download Build Artifacts
+        uses: actions/download-artifact@v3
+        with:
+          name: core-build
+          path: core/
+
+      - name: Deploy
+        run: yarn deploy --no-compile

README.md

@@ -1,9 +1,12 @@
 # litmus
+
 Bitcoin Liquid Staking
 
-# Development
+[![Core](https://github.com/thesis/litmus/actions/workflows/core.yaml/badge.svg?branch=main&event=push)](https://github.com/thesis/litmus/actions/workflows/core.yaml)
+
+## Development
 
-## Pre-commit Hooks
+### Pre-commit Hooks
 
 Developers are encouraged to use [pre-commit](https://pre-commit.com/) hooks to
 automatically discover code issues, before they submit the code.

core/.nvmrc

@@ -0,0 +1 @@
+lts/iron