AttributeError: 'Image' object has no attribute 'tostring'

[kexul]

Describe the bug
MolToImage not working

To Reproduce

Python 3.7.8 | packaged by conda-forge | (default, Nov 17 2020, 23:45:15) 
[GCC 7.5.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from rdkit import Chem 
>>> a = Chem.MolFromSmiles('CCCCC') 
>>> from rdkit.Chem.Draw import MolToImage
>>> b = MolToImage(a)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/data/miniconda3/envs/uii/lib/python3.7/site-packages/rdkit/Chem/Draw/__init__.py", line 101, in MolToImage
    img, canvas = _createCanvas(size)
  File "/data/miniconda3/envs/uii/lib/python3.7/site-packages/rdkit/Chem/Draw/__init__.py", line 56, in _createCanvas
    canvas = Canvas(img)
  File "/data/miniconda3/envs/uii/lib/python3.7/site-packages/rdkit/Chem/Draw/cairoCanvas.py", line 147, in __init__
    imgd = getattr(image, 'tobytes', image.tostring)("raw", "BGRA")
AttributeError: 'Image' object has no attribute 'tostring'

Configuration (please complete the following information):

• RDKit version: 2019.09.3
• OS: centos
• Python version (if relevant): 3.7.8
• Are you using conda? yes
• If you are using conda, which channel did you install the rdkit from? conda-forge

[greglandrum]

This has been fixed in the most recent version of the RDKit: 2020.03.1