test tube and ci (#13)

# Description
Added CI for testing the contract using the test-tube.
Added tests to initial version of contract.

# Reviewers checklist:
- [ ] Try to write more meaningful comments with clear actions to be
taken.
- [ ] Nit-picking should be unblocking. Focus on core issues.

# Authors checklist
- [x] Provide a concise and meaningful description
- [x] Review the code yourself first, before making the PR.
- [x] Annotate your PR in places that require explanation.
- [x] Think and try to split the PR to smaller PR if it is big.

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.github/workflows/contract-ci.yml

@@ -0,0 +1,31 @@
+name: contract-ci
+on:
+  push:
+    branches: ["master"]
+  pull_request:
+    branches: ["master"]
+  workflow_dispatch:
+env:
+  CARGO_TERM_COLOR: always
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Optimize contract
+        # TODO: Update it to Make file command
+        run: |
+          cd contract
+          docker run --rm -v "$(pwd)":/code \
+            --mount type=volume,source="$(basename "$(pwd)")_cache",target=/target \
+            --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
+            cosmwasm/rust-optimizer:0.14.0
+      - name: Run clippy
+        run: cargo clippy --verbose
+        working-directory: contract
+      - name: Build
+        run: cargo build --verbose
+        working-directory: contract
+      - name: Run tests
+        run: cargo test --verbose
+        working-directory: contract

contract/.gitignore

@@ -1,5 +1,6 @@
 # Build results
 /target
+/artifacts
 
 # IDEs
 .vscode/