add *.gem into .gitignore in gem template
add *.gem into .gitignore in gem template

jjaffeux/RubyMotion,beni55/RubyMotion,katsuyoshi/RubyMotion,katsuyoshi/RubyMotion,beni55/RubyMotion,hboon/RubyMotion,incbee/RubyMotion,katsuyoshi/RubyMotion,hboon/RubyMotion,beni55/RubyMotion,HipByte/RubyMotion,incbee/RubyMotion,jjaffeux/RubyMotion,jjaffeux/RubyMotion,HipByte/RubyMotion,beni55/RubyMotion,incbee/RubyMotion,katsuyoshi/RubyMotion,HipByte/RubyMotion,hboon/RubyMotion,incbee/RubyMotion,jjaffeux/RubyMotion