Updates for building on Travis CI and misc bug fixes

* Corrected some misc issues with the test suites
* Add phantomjs to defualt grid config
* Add install-ios-driver shell script for cloning, building, and
  installing ios-driver to local maven repository
* fix #17 - issues running SeLion client tests since latest ios-driver
  SNAPSHOT
* fix #18 - unsupported command-line displayed in chrome
* fix #19 - issues with WindowsProcessHandler
* fix #20 - chromedriver not found due to hard-coded assumption in
  SeLion server component