Merge pull request #30 from ngoldman/master

invalid auth fails silently
dont set refresh token unless deviceToken exists
version bump to 1.5
merge lastest changes from master
Merge pull request #32 from patrickarlt/master

dont set refresh token unless deviceToken exists
version 1.0.0 with tracking headers
Merge pull request #33 from patrickarlt/master

Tracking headers, version 1.0.0
update changelog for v1.0.0