Add OAuth2 authenticator using BitBucket
Add OAuth2 authenticator using BitBucket

thanks to Matthew Turk for figuring it all out
willjharmer/oauthenticator,Xarthisius/oauthenticator,NickolausDS/oauthenticator,minrk/oauthenticator,luisfdez/oauthenticator,willjharmer/oauthenticator,cmclaughlin/oauthenticator,jupyter/oauthenticator,cmclaughlin/oauthenticator,luisfdez/oauthenticator,santi81/oauthenticator,jupyter/oauthenticator,zonca/oauthenticator,yuvipanda/mwoauthenticator,yuvipanda/mwoauthenticator,zonca/oauthenticator,Xarthisius/oauthenticator,maltevogl/oauthenticator,enolfc/oauthenticator,jupyterhub/oauthenticator,santi81/oauthenticator