v2.0.0 Beta 2

• Node v8 support (package.lock.json added, and 8 added to node versions in travis config)
• credential support for login method - #186
• createUserProfile called with Facebook authentication - #187
• Switched back to using constructor to set context vars (attempt to fix undefined vars in componentWillMount)
• Merged changes that set displayName and wrappedComponent
• Docs sections redux-observable and epics combined
• Docs updated with changes to compose function (no longer supports passing fbConfig)
• Docs added about presence and sessions config options