<bugfix/auth> fix auth in requests #143
<bugfix/auth> set Authenticator in ExecAsync #143
<bugfix/auth> update build version #143
<stable/0.1> Merge branch 'bugfix/auth' into stable/0.1
<feature/sync-engine> Merge branch 'stable/0.1' into feature/sync-engine

Conflicts:
	DralloApp/IOs/Drallo.Lib.iOS/ApplicationContext.cs
	DralloApp/IOs/Drallo.Lib.iOS/Drallo.Lib.iOS.csproj
	DralloApp/IOs/Drallo.Lib.iOS/Net/Rest/ChallengeRestStore.cs