Fixes, Round 1

[mistergone]

This PR fixes the following bugs:

• Grad PLUS interest not appear
• Grad PLUS not imported from URL query string
• Grad PLUS not being included in calculations
• Tuition Payment Plans not included in monthly payments
• Tuition Payment Plans double-counted in summaries
• Expenses section not recalculating

  Changes

• Changed references of gradplus (and related) to gradPlus
• Added calls to expensesView.updateView()
• Added Tuition Payment Plan values to totals
• Updated student-debt-calc to latest version

  Testing

• Pull it down, npm install, and gulp, and then check out grad PLUS loans, tuition payment plan totals, monthly payments, and the expenses section total recalculation!

  Review

• @marteki @higs4281

  Checklist

• [x] Changes are limited to a single goal (no scope creep)
• [x] Code can be automatically merged (no conflicts)
• [x] Code follows the standards laid out in the front end playbook
• [x] Passes all existing automated tests
• [x] New functions include new tests
• [x] New functions are documented (with a description, list of inputs, and expected output)
• [x] Placeholder code is flagged
• [x] Visually tested in supported browsers and devices
• [x] Project documentation has been updated (including the "Unreleased" section of the CHANGELOG)

[coveralls]

Coverage remained the same at 99.766% when pulling 388e3c6b545c5aefe0909753e6cf541b5b02495a on fixes1 into 820b2c4a6aaf34e6dcb7a5735b1de4752ac940d2 on master.

[coveralls]

Coverage remained the same at 99.766% when pulling f7690427795e23e3a0adf22b7ca84bb3a4a3a092 on fixes1 into 820b2c4a6aaf34e6dcb7a5735b1de4752ac940d2 on master.

[marteki]

All six bugs tested across certificate, undergraduate, and graduate programs. All appear to be working as intended!

There is weirdness with the Perkins loan section appearing for graduate programs (when they shouldn't be, because grad programs aren't eligible for them), but that might be a separately tracked bug.

I also noted that it would be better if we didn't just copy-paste and duplicate sections of code, when it's already available in the codebase to be called. After that change is made, :+1: for merge.

[mistergone]

Merging, filed an issue internally relating to the duplicated code of updateElement()

[higs4281]

late to party, but it tested out for me 👍