integration test: initial commit

test/contract/contracts/Greeter.sol

@@ -0,0 +1,21 @@
+//SPDX-License-Identifier: Unlicense
+pragma solidity ^0.7.0;
+
+contract Greeter {
+  string greeting;
+
+  event Greet(string value);
+
+  constructor(string memory _greeting) {
+    greeting = _greeting;
+  }
+
+  function greet() public view returns (string memory) {
+    return greeting;
+  }
+
+  function setGreeting(string memory _greeting) public {
+    greeting = _greeting;
+    emit Greet(greeting);
+  }
+}