Reporting fixes

RPS -> RPS sent (the number of requests sent in the last N seconds)
Requests made -> Requests completed

Report concurrency

Update contributing guide

Fix parsing of flags in 'artillery quick'

* Remove whitespace
* Remove .gitattributes

* Vagrantfile updating gitignore
* adding global node modules
* adding git attributes
* Fixing gitattributes
* one more time
* changing to ubuntu

Issue 72 csv