Upgrade testing libraries

- Upgrade mocha
- Remove should due to limited usage and old style (at least by rspec standards)
- Move spec -> test which is the default
- Update tests accordingly for the above

test/document_handler_spec.js

@@ -0,0 +1,26 @@
+/* global describe, it */
+
+var assert = require('assert');
+
+var DocumentHandler = require('../lib/document_handler');
+var Generator = require('../lib/key_generators/random');
+
+describe('document_handler', function() {
+
+  describe('randomKey', function() {
+
+    it('should choose a key of the proper length', function() {
+      var gen = new Generator();
+      var dh = new DocumentHandler({ keyLength: 6, keyGenerator: gen });
+      assert.equal(6, dh.acceptableKey().length);
+    });
+
+    it('should choose a default key length', function() {
+      var gen = new Generator();
+      var dh = new DocumentHandler({ keyGenerator: gen });
+      assert.equal(dh.keyLength, DocumentHandler.defaultKeyLength);
+    });
+
+  });
+
+});