Add tutorials stage to travis build (#1022) (#1032)
Add tutorials stage to travis build (#1022) (#1032)

* add tutorials stage to travis build

* fix doctest that assumes Dataset.attrs is OrderedDict

* get into the right directory.

* install additional dependencies
landlab/landlab,cmshobe/landlab,amandersillinois/landlab,cmshobe/landlab,landlab/landlab,cmshobe/landlab,landlab/landlab,amandersillinois/landlab