Clean up npm package (#904)

* ignore everything but official contracts for npm

* add tests to npm package

* remove truffle migrations stuff

* remove seemingly unused npm dependency

* clean up dependencies

migrations/1_initial_migration.js

@@ -1,5 +0,0 @@
-var Migrations = artifacts.require('Migrations');
-
-module.exports = function (deployer) {
-  deployer.deploy(Migrations);
-};

migrations/2_deploy_contracts.js

@@ -1,9 +0,0 @@
-// var Ownable = artifacts.require("Ownable");
-
-// NOTE: Use this file to easily deploy the contracts you're writing.
-//   (but make sure to reset this file before committing
-//    with `git checkout HEAD -- migrations/2_deploy_contracts.js`)
-
-module.exports = function (deployer) {
-  // deployer.deploy(Ownable);
-};