1244 Checkbox Testing

[eburdekin]

Fixes #1244

Changes made:

Added tests for the following:

• Checkbox sets up correctly
  • Checkbox renders
  • renders correct initial state
• Checkbox functions correctly
  • clicking checkbox changes state
  • clicking checkbox does NOT change state of other checkboxes (multi-select is possible)
• Checkbox props are passed correctly
  • id passes correctly
  • label passes correctly
• Checkbox is accessible
  • checkbox is focus-able
  • using spacebar changes state
  • does not trap focus (pressing tab with more than one focus-able element present will move focus to next available element)

Reason for changes:

We want to retroactively implement testing to better protect our codebase

[sydneywalcoff]

@eburdekin Yay!! These look great!! Thank you for knocking this out!