Created working webpage through ERB and Sinatra.

-Added 2 get conditionals and 2 post conditionals to server.rb:
1. for the main page, '/', on get, displays all albums + form
2. for the main page, '/', on post, saves form element to database
3. for the albums page '/albums/:id', on get, displays the album, form and songs of the album
4. for the albums page, on post, saves the song to database with refrence id to album_id
-Completed ERB/HTML page for both index.erb and album.erb
-For both post request, redirects back to their respective pages.