Moar options: REST format, custom headers

[aseemk]

Fixes #10
Fixes #13

Simplified implementation from what I proposed in the issues in a few minor ways.

TAL and LMK if anything needs changing. Thanks!

[aseemk]

The tests pass for me locally, but some of the tests (all pre-existing) are timing out on Travis. Is that expected?

https://travis-ci.org/brian-gates/cypher-stream/builds/48833527

[coveralls]

Coverage increased (+0.66%) to 92.46% when pulling 7ee8a1c on aseemk:options-api into d6f50a1 on brian-gates:master.

[aseemk]

Checked in a mocha.opts file to increase the global Mocha timeout to 5 secs, up from the default of 2s (and the "slow" marker to 1s, up from 75ms), for Travis. Tests pass now. Hope that's cool?

[brian-gates]

Looks good; I've made you a contributor by the way, so feel free to continue development as needed :)

[aseemk]

Thanks @brian-gates!