[LIBCLOUD-739] Add DNSimple provider implementation

[aleGpereira]

Tests seems to be fine but i've got failures for tests against python 3.x. I couldn't fix this because i wasn't able to figure out why is doing the following error:

Traceback (most recent call last):
File "setup.py", line 285, in
'Programming Language :: Python :: Implementation :: CPython'
File "/usr/lib/python3.4/distutils/core.py", line 148, in setup
dist.run_commands()
File "/usr/lib/python3.4/distutils/dist.py", line 955, in run_commands
self.run_command(cmd)
File "/usr/lib/python3.4/distutils/dist.py", line 974, in run_command
cmd_obj.run()
File "setup.py", line 133, in run
status = self._run_tests()
File "setup.py", line 179, in _run_tests
tests = TestLoader().loadTestsFromNames(testfiles)
File "/usr/lib/python3.4/unittest/loader.py", line 146, in loadTestsFromNames
suites = [self.loadTestsFromName(name, module) for name in names]
File "/usr/lib/python3.4/unittest/loader.py", line 146, in
suites = [self.loadTestsFromName(name, module) for name in names]
File "/usr/lib/python3.4/unittest/loader.py", line 114, in loadTestsFromName
parent, obj = obj, getattr(obj, part)
AttributeError: 'module' object has no attribute 'test_dnsimple'

Maybe one of you guys can have a better clue?

[Kami]

Fixed Python 3 compatibility issue (0744dba) and merged changes into trunk.

Thanks!