chore(tests): add . as base path for browserify

This allows us to reference files in (lib|test)/* via absolute path
names.

test/config/karma.unit.js

@@ -1,9 +1,16 @@
 'use strict';
 
+var path = require('path');
+
+var basePath = '../../';
+
+var absoluteBasePath = path.resolve(path.join(__dirname, basePath));
+
+
 module.exports = function(karma) {
   karma.set({
 
-    basePath: '../../',
+    basePath: basePath,
 
     frameworks: [ 'browserify',
                   'mocha',
@@ -32,6 +39,7 @@ module.exports = function(karma) {
     // browserify configuration
     browserify: {
       debug: true,
+      paths: [ absoluteBasePath ],
       transform: [ [ 'stringify', { global: true, extensions: [ '.bpmn', '.xml', '.css' ] } ] ]
     }
   });