Migrate to DSS Python 0.10

[PMeira]

This integrates with DSS Python 0.10.0 (just released).

Closes #32, closes #36, closes #39.

[PMeira]

Weird... Python 3.6.7 introduces changes in how paths are handled on Windows and it breaks one test.

>       assert os.path.abspath(dss.Basic.DataPath()) == os.path.abspath(".")
E       AssertionError: assert 'C:\\projects...ssdirect-py\\' == 'C:\\projects\...ndssdirect-py'
E         - C:\projects\opendssdirect-py\
E         ?                             -
E         + C:\projects\opendssdirect-py

Seems like a bug since the behavior is not consistent on Linux:

Python 3.6.7 |Anaconda, Inc.| (default, Oct 23 2018, 19:16:44)
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.path.abspath('/tmp/'), os.path.abspath(".")
('/tmp', '/tmp')
>>> os.path.abspath('/tmp/'), os.path.abspath("./")
('/tmp', '/tmp')

[kdheepak]

Ugh that's unfortunate. If we can make it dss.Basic.DataPath().strip(os.path.sep) before calling os.path.abspath on the result and the tests pass, I think we can merge.

[PMeira]

I added something similar, passed the tests locally. If it doesn't work, I'll update it to use strip.

It seems the bug is already fixed: https://bugs.python.org/issue34949