Playlist page

[courtneyeh]

Problem The Emergency Details page is not implemented

Changes Made

• Implements fully functional road trip playlist page implemented.
• Users can authorise their Spotify account and give access to the web app.
• Allows an organiser to create a playlist.
• Allows users to see the playlist.
• Allows a host to add songs to the playlist.
• Shows a default page to members of the road trip when there is no playlist created, and they are not the host.
• After an hour, the access token expires. The refresh token is used to allow a user to continue using the web app.

Closes #24 Closes #53