fix "example" directory spelling

Author: codebender

exmaple/Gemfile renamed to example/Gemfile

@@ -22,7 +22,7 @@ use Rack::Session::Cookie
 
 use OmniAuth::Builder do
   provider :fitbit_oauth2, ENV['FITBIT_CLIENT_ID'], ENV['FITBIT_CLIENT_SECRET'],
-    :scope => 'activity sleep'
+    :scope => 'profile activity sleep'
 end
 
 run App.new