Added join_team schema for join requests.
Added join_team schema for join requests.

royragsdale/picoCTF,picoCTF/picoCTF,picoCTF/picoCTF,royragsdale/picoCTF,picoCTF/picoCTF,royragsdale/picoCTF,royragsdale/picoCTF,royragsdale/picoCTF,royragsdale/picoCTF,picoCTF/picoCTF,royragsdale/picoCTF,picoCTF/picoCTF,picoCTF/picoCTF