Update README to remove incorrect image link
Update README to remove incorrect image link

Removing the img that doesn't work and replacing with just the link to Browserstack, per their instructions.
emberjs/ember.js,stefanpenner/ember.js,knownasilya/ember.js,mixonic/ember.js,mfeckie/ember.js,emberjs/ember.js,tildeio/ember.js,tildeio/ember.js,sandstrom/ember.js,mfeckie/ember.js,stefanpenner/ember.js,sly7-7/ember.js,givanse/ember.js,givanse/ember.js,GavinJoyce/ember.js,mfeckie/ember.js,mixonic/ember.js,knownasilya/ember.js,asakusuma/ember.js,sly7-7/ember.js,sandstrom/ember.js,stefanpenner/ember.js,mfeckie/ember.js,elwayman02/ember.js,GavinJoyce/ember.js,elwayman02/ember.js,asakusuma/ember.js,givanse/ember.js,tildeio/ember.js,knownasilya/ember.js,sandstrom/ember.js,GavinJoyce/ember.js,asakusuma/ember.js,GavinJoyce/ember.js,sly7-7/ember.js,elwayman02/ember.js,asakusuma/ember.js,mixonic/ember.js,elwayman02/ember.js,givanse/ember.js,emberjs/ember.js