Simplify down to just AuthAction

i.e. with this model, this allows us to map directly onto the default Play way of doing authentication.
Remove GoogleAuthResult and expose what we need in UserIdentity;
avatarUrl
Update README to reflect lack of NonAuthAction
Align scala version for example application
Add change notice to README and update versions.
Merge pull request #9 from guardian/pw-simplify-actions

Simplify down to just AuthAction
Merge pull request #7 from janua/expose-user-info

Expose UserInfo through GoogleAuthResult
Add max auth age from PR #3
Merge pull request #12 from guardian/sihil-max-auth-age

Add max auth age from PR #3
Setting version to 0.1.5
Setting version to 0.1.6-SNAPSHOT
Updated latest released version in README
Bump version that example project uses to 0.1.3
Add cross compiling options
WIP
WIP