Fix heatmap range slider bug [Closes #380]

[cjchirag7]

Description

• Whenever user changes the field or mode, heatmap.resize() is called, so as to produce the desired results and fix the bug.
• The bounding box has been initialised at the beginning

Motivation and Context

• Fixes Range and value of sliders in heatmap get frozen in some cases [BUG]  #380

How Has This Been Tested?

• Tested in both Chrome and Firefox
• Also, the bounding box was not initialised at the beginning earlier, resulting in slower loading of the page

Screencast :

Types of changes

**What types of changes does your code introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

**Go over all the following points, and put an x in all the boxes that apply.
**(If you're unsure about any of these, don't hesitate to ask. We're here to help!)

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[cjchirag7]

Little surprising! Just removing unnecessary console logs made to pass the unit tests 😀

[birm]

Thanks for noticing and fixing this. 😃