Updated mocha browser version to latest.
Updated mocha browser version to latest.

fotinakis/testem,Addepar/testem,bradleylandis/testem,fotinakis/testem,johanneswuerbach/testem,johanneswuerbach/testem,paulot/testem,bradleylandis/testem,paulot/testem,paulot/testem,testem/testem,fotinakis/testem,testem/testem,johanneswuerbach/testem,bradleylandis/testem,Addepar/testem,Addepar/testem,Addepar/testem,testem/testem