Fix tests: Allow single files to be run

test/mocha.opts

@@ -1 +1 @@
---require test/mocha_node_setup.js --reporter spec test/models/*.js
+--require setup/node.js --reporter spec

test/mocha_node_setup.js

@@ -1,27 +0,0 @@
-if (!!global) {
-  global.chai = require('chai');
-  global.sinon = require('sinon');
-  global.bitcore = require('bitcore');
-  global.expect = global.chai.expect;
-  global.bignum = global.bitcore.Bignum;
-  global.should = global.chai.should();
-
-  try {
-    global.copay = require('copay');
-    global.copayConfig = require('config');
-  } catch (e) {
-    global.copay = require('../copay');
-    global.copayConfig = require('../config');
-  }
-
-  global.requireMock = function(name) {
-    try {
-      return require('../mocks/' + name);
-    } catch (e) {
-      return require('./mocks/' + name);
-    }
-  }
-
-  global.is_browser = typeof process == 'undefined' || typeof process.versions === 'undefined';
-  global._ = require('underscore');
-}