YTAnalytics 0.2.0

• Added error checking functionality when reading in a token file. Previously a token file would be read in and print a message saying that the token was successfully read, but if the token was expired the user wouldn't know until making a request.
• Added a progress bar to help track progress when passing vectors of video/playlist ids
• Added the playlist_metadata function.
• Fixed misc bugs like incorrect parameters being passed to functions or passing parameters that didn't exist
• Added github pages website (davisj95.github.io/YTAnalytics)
• Removed documentation for internal functions that aren't meant to be called directly