Add Category Drop-Down Menu (Creating NEW Inventory Items)

[pdxdiaperbank]

Desired/Expected behavior

When adding a new inventory item into Diaper Base, there should be a drop-down list of current/existing categories to "file" it under. If the category that the person wants doesn't exist, there should be an ability to add a new category.

Actual behavior

Currently, you type in a desired category in which you'd like it to fall under. This can create too many new categories, as well as inconsistencies.

Steps to reproduce the problem

Create a new inventory item entry.

Computer Information (Only fill this out if you are a diaper bank)

MacOS High Sierra
10.13.4
Browser: Chrome

[pdxdiaperbank]

Thanks for tackling this, @chiefkikio !

[armahillo]

@chiefkikio -- hold off on this until I finish #314 (nearly done)

[armahillo]

@chiefkikio If you would like to tackle this one, have at it!