Ignore my application constant file.
Added base class for requests

Refactoring
Added general StravaRequest object
Added specialised request object for an athlete
Pure Swift classes, no need for adding Obj-C functionality for these classes, they are used internal only.
Make use of the network engine.
Refactoring
Added Network Engine
Make use of singleton syntax for the StravaClient
Merge pull request #7 from elmoswelt/elmar/development

Elmar/development