Matplotlib Deprecation Warning from traceplot

[JohnPaton]

Description of your problem

pm.traceplot is causing deprecation warnings from matplotlib >= 3.0. Seems the 'ymin' keyword is being replaced. I haven't checked other plotting functions but I guess this will show up elsewhere as well.

Please provide a minimal, self-contained, and reproducible example.

import pymc3 as pm
with pm.Model() as m:
    a = pm.Normal('a', 0,1)
    trace = pm.sample(1000, tune=1000)
    
pm.traceplot(trace);

Auto-assigning NUTS sampler...
Initializing NUTS using jitter+adapt_diag...
Multiprocess sampling (4 chains in 4 jobs)
NUTS: [a]
Sampling 4 chains: 100%|██████████| 8000/8000 [00:01<00:00, 4286.79draws/s]

Please provide the full traceback.

/Users/johnpaton/.../python3.7/site-packages/matplotlib/axes/_base.py:3604: MatplotlibDeprecationWarning: 
The `ymin` argument was deprecated in Matplotlib 3.0 and will be removed in 3.2. Use `bottom` instead.
  alternative='`bottom`', obj_type='argument')

Please provide any additional information below.

Versions and main components

• PyMC3 Version: 3.5

• Theano Version: 1.0.3

• Python Version: 3.7.0

• Operating system: OSX

• How did you install PyMC3: pip

• Matplotlib version: 3.0.2