Merge branch 'master' into branch_lin
Add class librarian
Merge branch 'master' into branch_lin
Finished check book exist function
Merge branch 'master' into branch_lin
Finished first half of generate report function
Merge pull request #18 from g2-aj/branch_lin

Branch lin
Merge branch 'master' of https://github.com/g2-aj/cs304 into g3-ks