instead of setting it as the authentication policy directly
Also add command to make travis retry bundle install due to frequent network timeouts.
The callback code could possibly fetch the wrong profile if the authentication policy (and the sanction client) is shared between different threads. If there is only one sanction client and multiple users trying to authenticate, we might end up using the someone else's token to fetch a user's profile. The solution is to not initialize the sanction client at configuration time and to create a local client in the authentication code whenever we need one.
To use the stub policy, set "openstax_accounts.stub = true" in development.ini The default username is "test" and the default password is "password", but can be overridden by setting "openstax_accounts.stub.username" and "openstax_accounts.stub.password". The profile can be set in "openstax_accounts.stub.profile" in json format. Close #2