python2 LINUX (probably MAC too) broken in py3 merge branch

[doutriaux1]

env on linux created with:

conda create -n py2 -c uvcdat/label/nightly -c conda-forge -c uvcdat cdms2 cdat_info udunits2 nose flake8

gets us nightly cdtime:

c(py2) doutriaux1@drdoom:[/git/genutil]:[python3_continued]:[7080]> conda list cdtime
# packages in environment at /home/doutriaux1/anaconda2/envs/py2:
#
cdtime                    2.12.2017.10.03.11.24.47fd4557e455850a34c7fab5546e8ebe982b615a np111py27h6ee658f_0    uvcdat/label/nightly

Script to use:

import cdtime
c = cdtime.comptime(2017)
c2 = cdtime.comptime(2017)
c.cmp(c2)
c == c2

with 2.12

In [1]: import cdtime
In [2]: c = cdtime.comptime(2017)
In [3]: c2 = cdtime.comptime(2017)
In [4]: c.cmp(c2)
Out[4]: 0
In [5]: c == c2
Out[5]: True

with nightly py3ed:

>>> import cdtime
>>> c = cdtime.comptime(2017)
>>> c2 = cdtime.comptime(2017)
>>> c.cmp(c2)
0
>>> c == c2
False

Last == fails

[doutriaux1]

@dnadeau4, I added a test in #9 please let's work in that branch

[dnadeau4]

works in python 3, can not make operator work in python 2 due to different type of c and c2.