Repository: plotly/plotly.py

Issue:
Matplotlib Figure object not supporting 'validate' and 'strip_style'
Matplotlib `Figure` object is not supporting `validate` method 
https://github.com/plotly/plotly.py/blob/dbe8adb18a59cf7b57bbcb6d60841881da860518/plotly/plotly/plotly.py#L282

Sample Code:
```
fig, ax = plt.subplots()
ax.plot(y0, label='y0')
ax.plot(y1, label='y1')
ax.plot(y2, label='y2')
ax.plot(capacity, label='capacity')

# set all traces' "fill" so that it fills to the next 'y' trace
update = {'data':[{'fill': 'tonexty'}]}

# strip style just lets Plotly make the styling choices (e.g., colors)
plot_url = py.iplot_mpl(fig, update=update, filename='mpl-stacked-line')
```


Error:
```
site-packages\plotly\plotly\plotly.pyc in iplot_mpl(fig, resize, strip_style, update, **plot_options)
    280     if update and isinstance(update, dict):
    281         fig.update(update)
--> 282         fig.validate()
    283     elif update is not None:
    284         raise exceptions.PlotlyGraphObjectError(

AttributeError: 'Figure' object has no attribute 'validate'
```
And for `strip_style` https://github.com/plotly/plotly.py/blob/dbe8adb18a59cf7b57bbcb6d60841881da860518/plotly/plotly/plotly.py#L257

Sample Code:
```
plot_url = py.iplot_mpl(fig, update=update, strip_style=True, filename='mpl-stacked-line')
```

Error:
```
C:\Anaconda\Anaconda2\lib\site-packages\plotly\plotly\plotly.pyc in iplot_mpl(fig, resize, strip_style, update, **plot_options)
    277 
    278     """
--> 279     fig = tools.mpl_to_plotly(fig, resize=resize, strip_style=strip_style)
    280     if update and isinstance(update, dict):
    281         fig.update(update)

C:\Anaconda\Anaconda2\lib\site-packages\plotly\tools.pyc in mpl_to_plotly(fig, resize, strip_style, verbose)
    467             renderer.resize()
    468         if strip_style:
--> 469             renderer.strip_style()
    470         if verbose:
    471             print(renderer.msg)

C:\Anaconda\Anaconda2\lib\site-packages\plotly\matplotlylib\renderer.pyc in strip_style(self)
    737     def strip_style(self):
    738         self.msg += "Stripping mpl style, deleting keys from data and layout\n"
--> 739         self.plotly_fig.strip_style()

AttributeError: 'Figure' object has no attribute 'strip_style'
```


Discussion:
Hasn't the problem solved yet?
I have same problem.

code(it is the tutorial of "mne" module, ref→ https://plot.ly/ipython-notebooks/mne-tutorial/ )
```python
picks = mne.pick_types(raw.info, meg='mag', exclude=[])
data, times = raw[picks[:10], start:stop]

import matplotlib.pyplot as plt
import plotly.plotly as py

plt.plot(times, data.T)
plt.xlabel('time (s)')
plt.ylabel('MEG data (T)')

update = dict(layout=dict(showlegend=True), data=[dict(name=raw.info['ch_names'][p]) for p in picks[:10]])
py.iplot_mpl(plt.gcf(), update=update)
```

error: 
```
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-13-bb858f00c877> in <module>()
     10 
     11 update = dict(layout=dict(showlegend=True), data=[dict(name=raw.info['ch_names'][p]) for p in picks[:10]])
---> 12 py.iplot_mpl(plt.gcf(), update=update)

/usr/local/lib/python3.7/site-packages/plotly/plotly/plotly.py in iplot_mpl(fig, resize, strip_style, update, **plot_options)
    277     if update and isinstance(update, dict):
    278         fig.update(update)
--> 279         fig.validate()
    280     elif update is not None:
    281         raise exceptions.PlotlyGraphObjectError(

AttributeError: 'Figure' object has no attribute 'validate'
```

environment:
```
Mac OS 10.14.1
Python 3.7.0
mne 0.17.0 (install with pip3)
plotly 3.4.2 (install with pip3)
```

Resolving patch:
diff --git a/plotly/matplotlylib/renderer.py b/plotly/matplotlylib/renderer.py
--- a/plotly/matplotlylib/renderer.py
+++ b/plotly/matplotlylib/renderer.py
@@ -735,5 +735,4 @@ def resize(self):
                 pass
 
     def strip_style(self):
-        self.msg += "Stripping mpl style, deleting keys from data and layout\n"
-        self.plotly_fig.strip_style()
+        self.msg += "Stripping mpl style is no longer supported\n"
diff --git a/plotly/plotly/plotly.py b/plotly/plotly/plotly.py
--- a/plotly/plotly/plotly.py
+++ b/plotly/plotly/plotly.py
@@ -276,7 +276,6 @@ def iplot_mpl(fig, resize=True, strip_style=False, update=None,
     fig = tools.mpl_to_plotly(fig, resize=resize, strip_style=strip_style)
     if update and isinstance(update, dict):
         fig.update(update)
-        fig.validate()
     elif update is not None:
         raise exceptions.PlotlyGraphObjectError(
             "'update' must be dictionary-like and a valid plotly Figure "


Test patch: