[RM-1140] should not cache the vendor build directory for `rake build'
[RM-1140] should not cache the vendor build directory for `rake build'

`rake build' will create
  - build-AppleTVSimulator
  - build-AppleTVOS

However, if cache a first one, `rake build' will use simulator directory when build for device

hboon/RubyMotion,hboon/RubyMotion,HipByte/RubyMotion,HipByte/RubyMotion,katsuyoshi/RubyMotion,katsuyoshi/RubyMotion,hboon/RubyMotion,katsuyoshi/RubyMotion,HipByte/RubyMotion,katsuyoshi/RubyMotion