`DashStanExample()` is missing `sampledata.pkl`

[Munfred]

Hello, thanks for making this. I saw shinystan, and thought "wouldn't be too hard to make this for python using plotly dash...what would I call it? hmmm" then I Google dashstan and this is the first result.

After I installed, and tried running the demo DashStanExample() I got:

>>> from dashstan import DashStanExample
DashStanExample()
>>> DashStanExample()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/munfred/git/dashstan/dashstan/dashstan.py", line 81, in __init__
    with open(file_path, 'rb') as f:
FileNotFoundError: [Errno 2] No such file or directory: '/Users/munfred/git/dashstan/dashstan/sampledata/sampledata.pkl'
>>>

While looking for the sampledata.pkl file I realized it could be generated by just running /dashstan/sampledata/create_sample_data.py and then the demo runs without a problem. Looks very nice!

So my suggestion would be to just update the readme to mention that create_sample_data.py should be run before calling DashStanExample()

Now, I had one more generate question: What is the development status of dashstan? I noticed the last commit was a year ago and it doesn't seem to be in active development anymore. Do you consider it done, or was development stopped because of no bandwidth? This looks like it would be a valuable addition to pystan.

Thanks!