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
Fixed outport bug, add tomography module and update to latest VTTools

Merge remote-tracking branch 'upstream/master'