Using two fingers on touch enabled devices causes atom spread in molecules

[loganbraywork]

Test device
Hanson
Operating System
Windows 10
Browser
Chrome
Problem description
Similar to #118 but can lead to buggier behavior if two fingers continue to be used.
When two fingers are used on a built molecule it causes the atoms to change distance from each other but the molecule to not break apart which can lead to further buggy behavior
Steps to reproduce

1. Enter the lab screen
2. Build a molecule
3. Using a touch enabled computer, manipulate both atoms of the molecule simultaneously using two fingers
   Visuals
   

Troubleshooting information:

!!!!! DO NOT EDIT !!!!! Name: ‪Build a Molecule‬ URL: http://phettest.colorado.edu/build-a-molecule/build-a-molecule_en.html?ea&brand=phet Version: 0.0.0-dev.40 (require.js) Features missing: touch Flags: pixelRatioScaling User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.117 Safari/537.36 Language: en-US Window: 1280x610 Pixel Ratio: 2.5/1 WebGL: WebGL 1.0 (OpenGL ES 2.0 Chromium) GLSL: WebGL GLSL ES 1.0 (OpenGL ES GLSL ES 1.0 Chromium) Vendor: WebKit (WebKit WebGL) Vertex: attribs: 16 varying: 30 uniform: 4096 Texture: size: 16384 imageUnits: 16 (vertex: 16, combined: 32) Max viewport: 32767x32767 OES_texture_float: true Dependencies JSON: {}

[loganbraywork]

Can also cause a crash similar to #141 if spread out molecules are placed into the buckets

[Denz1994]

Can you confirm this is fixed in this dev version @loganbraywork?

[Denz1994]

Adding @KatieWoe to this confirm this issue, due to QA devices being moved between members. This dev version should have the same fixes from above. Atoms shouldn't be separated when dragging with two fingers.

[KatieWoe]

This issue seems fixed from what I can tell in that dev version

[Denz1994]

Nice. Closing.