Additional exercises to port

[BNAndras]

Here are some additional exercises I can port in early December once Vim script is in a good place.

• [ ] armstrong-numbers
• [ ] custom-set
• [ ] list-ops
• [ ] phone-number
• [ ] proverb
• [ ] resistor-color-trio
• [ ] rotational-cipher
• [ ] series
• [ ] sublist
• [x] allergies
• [x] binary-search
• [x] etl
• [x] perfect-numbers
• [x] reverse-string
• [x] robot-simulator
• [x] roman-numerals
• [x] square-root
• [x] strain

[BNAndras]

@ErikSchierboom, I have five exercises here for review.