fix(scrollIntoView): take bottom borders into account when scrolling

[arahansen]

What: scrolling offsets now take bottom border into account

Why:
Auto scrolling does not offset enough when using larger borders.

Example:

(dropdown borders exaggerated to demonstrate issue)

Before:

After:

How:
Added a check for border bottom to the scrollIntoView function

Checklist:

• Documentation (N/A)
• Tests
• Ready to be merged
• Added myself to contributors table

[codecov-io]

Codecov Report

Merging #138 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master   #138   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           3      3           
  Lines         259    260    +1     
  Branches       63     63           
=====================================
+ Hits          259    260    +1

Impacted Files	Coverage Δ
src/utils.js	100% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 72b8544...981ee20. Read the comment docs.

[kentcdodds]

Most excellent! Thank you!

[kentcdodds]

Would you like to add yourself to the contributors table?

[kentcdodds]

~/Developer/downshift (master)
🏎  $ npm publish --tag rc
+ downshift@1.0.0-rc.12