upgrade scrypt, node package for node 0.12.x support

[skorasaurus]

Installation of opendatacensus from master fails on node installations of 0.12.x
I've confirmed this twice, on my computer locally, and on a friend's (gist of install error).

The scrypt package (node-scrypt), at 1.7.4 in our master, doesn't support node >=0.11. Support for node 0.12 was added in barrysteyn/node-scrypt@223f039

I did a new install of opendatacensus with my updated package.json and was able to locally run it without noticeable problems. There were a couple notices in the terminal while running it.

Here's the results from my mocha test
and the [install log from npm]https://gist.github.com/b985622d1d3c878576f3

[skorasaurus]

Figuring out how to make a Travis test.

[skorasaurus]

@pwalsh
made a travis test off a branched based off this pull request and here are the results https://travis-ci.org/skorasaurus/opendatacensus/jobs/60959541

[pwalsh]

@skorasaurus thanks. I'll take it from here (there are problems in the tests due to the integration with Google Spreadsheets).

[pwalsh]

Hi @skorasaurus

Thanks for taking the time on this. I'm currently initiating a refactor of the codebase in order to move data out of Google Spreadsheets and into Postgres.

Because of the refactor, I don't want to merge any code into master right now.

But, I do intend to cherry pick this commit into the new branch for the refactor (as well as do the upgrade to Express 4, which is related to the other console warning you see).

[skorasaurus]

@pwalsh

Thank you for the update! I'm relieved to hear that work is still continuing on it.

[pwalsh]

@skorasaurus oh yes, work is definitely continuing. I'm going to close this pull request now. Thanks for helping find the issue there.