refactored tests for mocha and tweaked some internals

[davglass]

This is a pretty large PR 😄

I did:

• Convert test suite to mocha
• Required 100/100/100/100 code coverage
• Fixed a bug or two while getting to 100^4 code coverage
• Converted all of the if/else for handling errors to be if (err) { return callback(err); } style
• Enforced callback on cache.get
• Replaced deepCopy with lodash.close for perf.
• Some whitespace tweaks.
• Added Node 0.12, 4, 5 & 6 to travis config and removed 0.8
• Bumped the version to 1.0.0

[davglass]

Woot, tests are all passing now on all node versions..

[davglass]

@bengl @drewfish @vsacheti

[bengl]

might as well throw 5 in here. people are using it in prod.

[davglass]

Done

[bengl]

yay!

[bengl]

it may be worth stubbing the original dns functions so as to speed up these tests. we shouldn't be interested in testing that require('dns') works... (non-blocker)

[davglass]

Yeah, there are also some setTimeout's in the tests too that this was to account for.

[bengl]

yeah that's dangerous.

[bengl]

ok LGTM with the following caveats to be sorted out in later PRs:

• let's figure out what to do with errors
• tests can be sped up by stubbing
• factory-ize the wrappers
• ensure all the methods on dns are covered https://github.com/nodejs/node/blob/master/lib/dns.js#L247-L256

and one potential doozie (also a non-blocker):

• either carve out the cache itself into its own module, or use something like lru-cache.

[davglass]

Agreed on all points. I'll work on those items next. Let's just not publish 1.0.0 until we handle those.