WCMS-182 added timestamps to concentration
Added concentration factory and spec. fixed set_slug and slug validation
Merge branch 'master' into degree_program_concentrations
made suggested changes and set slug to nil rather than an empty string
Merge branch 'master' into degree_program_concentrations
simplified slug setting and added note referencing needed route manipulation
added description and curriculum fields
Merge pull request #92 from biola/degree_program_concentrations

Degree program concentrations