Tensorflow version requirement 1.1

[stefdoerr]

You can put in the docs that you need 1.1. Does not work with 1.4 as

ValueError: `tf.add_check_numerics_ops() is not compatible with TensorFlow control flow operations such as `tf.cond()` or `tf.while_loop()`

[jparkhill]

Stefan - I removed the numeric check ops and tested it's working in 1.4. Pretty bizzare google chose to break this compatibility which existed in < 1.3...

anyways, thanks for bringing it to my attention.

[stefdoerr]

Thanks!