Updated sendTransaction, added tests. (#1528)

* Renamed sendTransaction to send, improved API.

* Added send tests.

* Now using promisified web3

test/helpers/send.js

@@ -0,0 +1,26 @@
+const ethjsABI = require('ethjs-abi');
+const { ethSendTransaction } = require('./web3');
+
+function findMethod (abi, name, args) {
+  for (let i = 0; i < abi.length; i++) {
+    const methodArgs = abi[i].inputs.map(input => input.type).join(',');
+    if ((abi[i].name === name) && (methodArgs === args)) {
+      return abi[i];
+    }
+  }
+}
+
+async function transaction (target, name, argsTypes, argsValues, opts) {
+  const abiMethod = findMethod(target.abi, name, argsTypes);
+  const encodedData = ethjsABI.encodeMethod(abiMethod, argsValues);
+  return target.sendTransaction(Object.assign({ data: encodedData }, opts));
+}
+
+function ether (from, to, value) {
+  return ethSendTransaction({ from, to, value, gasPrice: 0 });
+}
+
+module.exports = {
+  ether,
+  transaction,
+};