#12 create model & migrate & rspec files
#12 remove setlist (wasteful relation model)
#12 add gems for test
#12 add factory_girl gem setting
Revert "#12 add factory_girl gem setting"

factory_girlは複雑さを増すだけなので削除

This reverts commit 0cc76e98af067ea9f8e8aa12f6d5bfc681c711ef.
Revert "#12 add gems for test"

factory_girlはテストを複雑にしすぎてしまうので削除
This reverts commit 3b320c187b1e2aa72670c306b38ed3824207b208.
#12 passed 'festival.artists'
#12 passed 'artist.festivals' :D
#12 create 'spec/common_helper.rb' for efficiency
#12 passed 'music.artist'
Merge branch 'create-skelton' into create-model
#12 deleted useless pended test
Merge branch 'create-skelton' into create-model
#13 cleaned testcase (made it more simple)
Merge branch 'create-skelton' into create-model
in the middle of test 'setlist'
#12 passed 'artist.setlist(festival)'
#12 passed 'festival.setlist(artist)'
#12 modify comment
#12 deleted models 'program' & 'music'