Add mocha, chai, and test for Contribution

test/Contribution.js

@@ -0,0 +1,19 @@
+const { expect } = require("chai");
+const { ethers, upgrades } = require("hardhat");
+let hardhatContribution;
+
+describe("Contribution contract", function () {
+
+  describe("Deployment", function () {
+    before(async function () {
+      // const [owner] = await ethers.getSigners();
+      const Contribution = await ethers.getContractFactory("Contribution");
+      hardhatContribution = await upgrades.deployProxy(Contribution, [40321]);
+    });
+
+    it("sets the veto confirmation period", async function () {
+      expect(await hardhatContribution.blocksToWait()).to.equal(40321);
+    });
+  });
+
+});