feat: support URL objects

`url.URL` was added in Node 7 and functions like `http.get()`,
`http.request()` accept URL objects as well as strings as their first
argument. Add support for that to nock.

fix: match HTTP headers with case insensitivity (nock#1122)

fix: remove arrow functions to restore Node<4 compatibility (nock#1114)

fix: url encoded body matches non-string values (nock#1110)

fix: PhantomJS 2 usage (nock#1075)

fix: Allow allowUnmocked = true and regexp paths to work (nock#1034)

build(package): -restify, +restify-clients

feat: support replay of recorded binary responses

fix: request timeout (nock#859)

fix: allowing dot notation parsing for x-www-form-urlencoded posts (n…

…ock#1063)