constrain tensorflow version

[andy-esch]

When installing edward using the default method (pip install edward) and using the tensorflow versions specified in the setup.py (tensorflow>=1.2.0rc0), I get the following for some of the get started code:

ModuleNotFoundError: No module named 'tensorflow.contrib'

Since Tensorflow released a v2.0 that has a different API, looks like the tensorflow dependency should be constrained to be <2.0 as is done here. This seems to work as expected but #882 is showing up when I run examples from the notebooks directory and elsewhere so perhaps this should be constrained further or that issue could be fixed in a separate PR.

Stacktrace

--------------------------------------------------------------------------- ModuleNotFoundError Traceback (most recent call last) in 1 import tensorflow as tf ----> 2 from edward.models import Normal 3 4 W_0 = Normal(loc=tf.zeros([1, 2]), scale=tf.ones([1, 2])) 5 W_1 = Normal(loc=tf.zeros([2, 1]), scale=tf.ones([2, 1]))

~/.local/share/virtualenvs/ed-61OcBILj/lib/python3.7/site-packages/edward/init.py in
3 from future import print_function
4
----> 5 from edward import criticisms
6 from edward import inferences
7 from edward import models

~/.local/share/virtualenvs/ed-61OcBILj/lib/python3.7/site-packages/edward/criticisms/init.py in
5 from future import print_function
6
----> 7 from edward.criticisms.evaluate import *
8 from edward.criticisms.ppc import *
9 from edward.criticisms.ppc_plots import *

~/.local/share/virtualenvs/ed-61OcBILj/lib/python3.7/site-packages/edward/criticisms/evaluate.py in
7 import tensorflow as tf
8
----> 9 from edward.models import RandomVariable
10 from edward.util import check_data, get_session, compute_multinomial_mode,
11 with_binary_averaging

~/.local/share/virtualenvs/ed-61OcBILj/lib/python3.7/site-packages/edward/models/init.py in
5 from future import print_function
6
----> 7 from edward.models.dirichlet_process import *
8 from edward.models.empirical import *
9 from edward.models.param_mixture import *

~/.local/share/virtualenvs/ed-61OcBILj/lib/python3.7/site-packages/edward/models/dirichlet_process.py in
6
7 from edward.models.random_variable import RandomVariable
----> 8 from tensorflow.contrib.distributions import Distribution
9
10 try:

ModuleNotFoundError: No module named 'tensorflow.contrib'

[harishkashyap]

+1 to this. This library didnt work on latest tensorflow 2.2+ and python3.8+. The older versions are missing links and so pip is also unable to find them. Best is to upgrade the library to work with latest python and tensorflow.