addd weixin_uploader.rb
added rmagick
upload media from remote
added fake date
Merge branch 'master' into upload-media-from-remote

Conflicts:
	lib/weixin_authorize.rb
	weixin_authorize.gemspec
can upload any kind picture
updated media_spec
add medias test file
added mini_magick
clear last one day cache
Merge pull request #20 from lanrion/upload-media-from-remote

[WIP] #17 Upload media from remote