Renamed setExpiresIn method to accessTokenTTL
Added method to set the auth token TTL
Added refresh token TTL
Renamed get/setExpiresIn to get/setAccessTokenTTL
Added refresh token expires column
Updated associateRefreshToken to use expire time
Test for setAuthTokenTTL
Test for setRefreshTokenTTL
Updated the README
Updated the changelog
Renamed namespace to League\OAuth2\
Updated tests for new namespace
Renamed package