add expression model into vistrails
add more test
BLD : add missing package
MNT : commented out mds dep for testing
BLD : first pass at setting up conda
MNT : remove unicode_literals, force to str

402c6d2d34c52b0ee7844c14701a8c9362e20d7b added an
explicit check of `isinstance(x, str)` which fails on
unicode in python2.  This breaks almost everything in wraplib
(even though it _used_ to work just fine).

 - removed unicode_literals
 - added explicit casts to str until it worked

This commit should be reverted at some point when VisTrails is fixed
Merge pull request #39 from tacaswell/conda

Conda
Merge pull request #35 from licode/expressModel

Express model
ENH: Changes to use enaml gui creation
Merge pull request #42 from ericdill/enaml

ENH: Changes to use enaml gui creation
DEV: Finished test function for define_input_ports in wrap_lib.py

Ended up only including the basic tests for the function. I have been
trying to come up with a test case that triggers the ValueError
starting on line 500, however, I have not been able to come up with
one thus far.
If necessary this can be revisited.
TST : cleaned up tests

 - moved tests to be in canonical location
 - added skip for windows-only tests
TST : simplified tests

Use generator tests where possible
ENH : rough draft of upgrades to type parsing

massive bad-form commit, but there is too much intertwined
code to split up.

 - moved to providing single function `_normalize_type` to
handle all of the type parsing
 - handle normalization via lots of regular expressions
 - handle of / or recursively
 - module-level precedence ordering
DEV: Finished test for define_output_ports function in wrap_lib.py
DEV: Updated wrap_lib to modified version contained in enum_test
BUG: Modified modules.yaml. Changed gauss_fit to gaussian_fit
BUG: Commented find_ring_center_acorr_iD in modules.yaml

A bug remains in find_ring_center_acorr_iD that prevents auto_wrapping.
This import statement has been commented out until the input/output
types can be converted, or added to the wrap_lib library of dtypes.
DEV: Created func to scrape default param values during autowrap

Function is called _default_vals.
This fuction will be used by the function define_input_ports when
functions are being autowrapped into VisTrails objects.
BUG: Commented modules.yaml entries that caused probs

These commented functions are temporary removals that should be fully
functional after default value assignment is merged into master