delete
fix
Merge branch 'bowen' into shuaiwang
Merge branch 'Bohan-Zheng' into shuaiwang
Merge branch 'master' into shuaiwang
Merge branch 'bowen' into shuaiwang
add find corerequsite
Merge branch 'Bohan-Zheng' into shuaiwang
Merge branch 'Bohan-Zheng' into shuaiwang
add core requisite
Merge branch 'shuaiwang' into Bohan-Zheng

Conflicts:
	app/models/StudyPlan.java