Upgrade to latest version of jasmine-node published on npm (1.7.1)

While "1.5.0" is the last tag published in jasmine-node project on GitHub [1],
the latest version published in npm is "1.7.1".

Several bugs have been addressed, including silent failures which I
encountered while modifying the unit tests on node v0.10.5 [3][4].

[1] GitHub: jasmine-node tags
https://github.com/mhevery/jasmine-node/tags

[2] npm: jasmine-node
https://npmjs.org/package/jasmine-node

[3] Error silenced when test not found/import inside test not found.
https://github.com/mhevery/jasmine-node/issues/212

[4] Jasmine-node silently fails with latest Node v0.10.4
https://github.com/mhevery/jasmine-node/issues/218