Improve Google Colab support

[cornhundred]

Google Colab does not currently support custom widgets - see googlecolab/colabtools#498 (comment). However, @blois made an example interactive figure using IPython.display (this will be useful for cases where widgets are not supported).

The following enhancements should be made:

• clean up IPython.display implementation (e.g. maybe make a net.colab method in clustergrammer2)
• move reorder buttons and control panel above heatmap
• get tooltip working
• figure out how to pre-load data into shareable notebook (@manugarciaquismondo has worked on this). Maybe we can use Kaggle data API, or public data on Google Drive, or Github.

This link shows an example of Clustergrammer visualizing a random matrix:
https://colab.research.google.com/gist/cornhundred/b7154ee964c71cec6a2378f9cbba8eeb/clustergrammer2_example.ipynb?authuser=1

[cornhundred]

We requested support here: googlecolab/colabtools#60 (comment)

[ranikay]

Any update on this @cornhundred ?

[blois]

Third-party widgets are now supported in Colab- is there an example of the widgets not working?

[cornhundred]

@ranikay this example shows how to get the Clustergrammer2 widget working on Google Colab https://colab.research.google.com/drive/11M6RkGuh-5zR9OVXgeDNKKHm440-DgTA

Thanks @blois for your work getting Widgets supported on Google Colab :)