Upgrade Bootstrap to version 4

[bklaing2]

Purpose

We are currently using Bootstrap 3, which is over a decade old. This PR upgrades it to Bootstrap 4

closes: Add github issue that originated this PR

Approach

Open Questions and Pre-Merge TODOs

Learning

Types of changes

• [ ] 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 change)

Reviewer, please remember our guidelines:

• Be humble in the language and feedback you give, ask don't tell.
• Consider using positive language as opposed to neutral when offering feedback. This is to avoid the negative bias that can occur with neutral language appearing negative.
• Offer suggestions on how to improve code e.g. simplification or expanding clarity.
• Ensure you give reasons for the changes you are proposing.

[cypress[bot]]

akita    Run #1350

Run Properties:   Passed #1350  •  f3ccc39b5e ℹ️: Merge 22feacfc7d33a024d84cb0a4d3c9fefa9c979dce into e754e3c6e14e3d24415ed7b88c8e...

Project	akita
Branch Review	testing-maltipoo
Run status	Passed #1350
Run duration	01m 35s
Commit	f3ccc39b5e ℹ️: Merge 22feacfc7d33a024d84cb0a4d3c9fefa9c979dce into e754e3c6e14e3d24415ed7b88c8e...
Committer	Bryceson Laing
View all properties for this run ↗︎

---

Test results
Failures	0
Flaky	0
Pending	3
Skipped	0
Passing	52
View all changes introduced in this branch ↗︎

[cypress[bot]]

akita    Run #1351

Run Properties:   Passed #1351  •  22feacfc7d: Merge branch 'master' into testing-maltipoo

Project	akita
Branch Review	testing-maltipoo
Run status	Passed #1351
Run duration	01m 32s
Commit	22feacfc7d: Merge branch 'master' into testing-maltipoo
Committer	Bryceson Laing
View all properties for this run ↗︎

---

Test results
Failures	0
Flaky	0
Pending	3
Skipped	0
Passing	52
View all changes introduced in this branch ↗︎