WIP: response parsers for different drivers in JsonDriver type

* New response parser for Selenium driver
* Set retries to 0 when creating or destroying session

Changes in Hound.JsonDriver.Utils

* Make decode_content public function
* make_req should use a driver's response parser
Add response parser for chromedriver
By default retries is 0 for all requests; Only finders require retries
Response parser for phantomjs
Remove logging response value
Remove unnecessary delete_cookies() call from cookies test setup
Run dialog tests only if the driver supports it
Start phantomjs
Tryout travis command
Determine path of phantomjs
phantomjs in bash script
install phantomjs from within the bash script
Ouch. Use -w option for phantomjs