Remove duplicate mime-types dep from Gemfile
Remove duplicate mime-types dep from Gemfile

The gemspec already specifies a version of mime-types.
Specifying it in the Gemfile is redundant and repetitive. :)

kaineer/mail,missive/mail,benmmurphy/mail,agaridata/mail,jeremy/mail,kjg/mail,jonkgrimes/mail,benmmurphy/mail,schepedw/mail,0x00evil/mail,carsonreinke/mail,owenr/mail,pjskennedy/mail,mikel/mail,0x00evil/mail,pushrax/mail,kert-io/mail,wktk/mail,jonkgrimes/mail,planio-gmbh/mail,kjg/mail,jeremyevans/mail,EdwardPantoja/mail,wktk/mail,jeremy/mail,jeremyevans/mail,schneems/mail,schepedw/mail,zacholauson/mail,EdwardPantoja/mail,pushrax/mail,kert-io/mail,carsonreinke/mail,agaridata/mail,smallspark/mail,pjskennedy/mail,schneems/mail,zacholauson/mail,kaineer/mail,smallspark/mail