Use prompt instead of argv arguments in scripts

This makes it easier to handle truffle arguments which we for example
need to specify the network.
So we ask the user for input instead on using the argv array which might
change.

scripts/send-funds.js

@@ -1,12 +1,12 @@
+const promptly = require('promptly');
+
+module.exports = async function(callback) {
+  let recipient = await promptly.prompt('Recipient address: ');
+  let amount = await promptly.prompt('Amount: ', {default: '1'});
+  amount = parseInt(amount);
+
+  console.log(`sending ${amount} ETH from ${web3.eth.accounts[0]} to ${recipient}`);
 
-module.exports = function(callback) {
-  let recipient = process.argv[4];
-  if (!recipient) {
-    console.log('Please provide a recipient address');
-    process.exit();
-  }
-  let amount = parseInt(process.argv[5]) || 1;
-  console.log(recipient);
   web3.eth.sendTransaction({to: recipient, value: web3.toWei(amount), from: web3.eth.accounts[0]}, console.log);
 
   callback();