added changes in CHANGELOG.md
bumped version to v0.7.10
added note about repo clean in changelog
download selenium server via http:
added instruction to use webdriverjs withBrowserStack
Fixed a wrong name on a local variable reference

The call to `this.requestHandler.create` used a non-existing variable (`requestOptions`) as the first argument. I think that the intention was to use the local var called `commandOptions` in the call ?
added Sauce Labs and BrowserStack examples
Merge pull request #82 from sgryt/patch-1

Fixed a wrong name on a local variable reference
added CONTRIBUTING.md
removed npm postinstall script because of missing support on windows machines, should be downloaded manually anyway
fixed wrong variable name
rewrote some README.md parts
bumped version
set value of input field via array of strings, enables proper use of modifier keys - refs issue #84
added more tests using modifier keys - refs issue #84
added description for improved commands in readme