Add hint to remaining @Ignore annotations

[FridaTveit]

Add a hint with the value "Remove to run test" to the @Ignore annotations that aren't covered by the good first patch issues:

• pangram
• gigasecond
• space-age
• acronym
• difference-of-squares
• secret-handshake
• matrix
• triangle
• largest-series-product
• sieve
• twelve-days
• nth-prime
• diamond
• isogram
• flatten-array
• phone-number
• accumulate
• nucleotide-count
• word-count
• robot-name
• allergies
• bob
• pascals-triangle
• bracket-push
• series
• atbash-cipher
• beer-song
• queen-attack
• etl
• linked-list
• grade-school
• robot-simulator
• binary-search
• minesweeper
• wordy
• all-your-base
• anagram
• sublist
• binary-search-tree
• rectangles
• meetup
• crypto-square
• simple-cipher
• palindrome-products

See issue #426 for discussion.

[mraediaz]

Will be working on linked-list.

[FridaTveit]

All of these are currently done or in review :)

[stkent]

@FridaTveit awesome work! I think this issue can be closed now?

[FridaTveit]

Looks like it :)