Account paths return a "user" object not an account object

Must be how rabl works with models
Updated README
Added #to_a to most App collection classes
Ignore unused parameters
Added health_check
Added Dawn.log and Dawn.debug
Hijack Excon errors instead of bypassing them
Patched destroy and delete methods
Updated gemspec
safe should return false on failure, returns the result of the call otherwise
data_key now returns the key_name
Added App#save and Account#save
Removed old App#git key
data_key now accepts a options Hash

New options are:
write: changes whether the key is writable or not
  default: true
read: changes whether the key is readable or not
  default: true
path: is the replacement for key_path
  default: key_name
#safe now accepts parameters

if parameters are given, safe is treated as a call to the first parameter
on the object, the return value is the result of the method call.
safe without parameters will return a SafeContext
request, use the exception's response body instead of the last_response_body
Update Dawn::Account

refresh returns self

Moved initialize below data_key calls
Update Dawn::App

keep @data hidden
moved #initialize below .data_key calls
#refresh and #update return self
one line include(s)
Update Dawn::Domain, same treatment as the others