Unable to drag fuse slider to end of slider

[KatieWoe]

Test device
Lovelace
Operating System
ChromeOS
Browser
Chrome
Problem description
For phetsims/qa#605.
When dragging the slider it increments by 1.0, but the arrows go by .1. This means that you can't drag the fuse to it's minimum setting. It stops at 1.0, but it's actual minimum is .5.
This was not an issue in the published version, which seems to be because the published sim increments this value by .5.
Steps to reproduce

1. Drag fuse out
2. Select fuse and use slider to try and minimize it's current rating
3. Use arrows to fully minimize the rating

Visuals

[arouinfar]

@samreid let's change the constrainValue to 0.5

[samreid]

In the commit, I round constrainValue to 0.5 instead of 1. It seems OK on my side. @arouinfar or @KatieWoe can you please review in master? If it is OK, please reassign to me so I can cherry pick into the RC.

[arouinfar]

Looks good @samreid.

[samreid]

This is ready for spot checking in the deployments listed for phetsims/qa#610, please close if it seems correct in RC.2.

[KatieWoe]

Looks good in rc.2