Merge pull request #139 from splattael/ruby-version

Add .ruby-version.
Merge pull request #140 from splattael/fix-approval-fixture

Fix approval javascript fixture broken in 651a8550.
Merge pull request #141 from splattael/readme-mailcatcher

Mention that `mailcatcher` must be up before running tests.
Merge pull request #142 from splattael/fix-startup-failure

Fix startup failure in development mode.
Merge pull request #163 from kytrinyx/next-assignment

Adjust 'level up' algorithm
Merge pull request #233 from rubysolo/clojure

better tests, improve examples
Merge pull request #231 from msgehard/go-roman-numerals

Add roman numerals in Go
Merge pull request #228 from kytrinyx/configure-email-address

Add email update functionality
add bob assignment
add rna transcription assignment
add wordcount assignment
use better method for translation in example
add anagram assignment
Merge pull request #277 from kytrinyx/rustlang

Convert assignments to Rust
Merge pull request #280 from rubysolo/clojure

add clojure/grains
add beer-song example
add nucleotide-count assignment
add point-mutations exercise
add phone-number assignment
Merge pull request #322 from rubysolo/elixir

add elixir/grains