Make miscellaneous revisions for version 1.3.5 (blei-lab#828)

* make miscellaneous revisions

* version 1.3.5

* fix pep8

version 1.3.4

Version 1.3.3 (blei-lab#680)

* make misc revisions

* note keras issue in docs/

* update n_iter docstring

* version 1.3.3

version 1.3.2

fix import error for edward.inferences.conjugacy

Update Edward to version 1.3.0 (blei-lab#623)

* version 1.3.0

* remove call to _ref now that tf.gradients uses as_ref=True in implementation

* make miscellaneous revisions

version 1.2.4

version 1.2.3

version 1.2.2

version 1.2.1