Add elixir list-ops
Remove obsolete elixir accumulate and strain

These exercises have been replaced by list-ops
Add list-ops back into OCaml
Add specs to linked-list_test.spec.js 

Flesh out the linked-list spec in JavaScript:
- Change Deque to LinkedList
- Add specs to test count() and delete() functions.
Update test name in javascript phone-number. Fixes #1259.
Add link to language list on new homepage
Merge pull request #1255 from pminten/elixir-list-ops

Add Elixir list ops and remove accumulate and strain
create passing example for new linked list spec in javascript
Merge pull request #1256 from fluxusfrequency/patch-1

Add specs to linked-list_test.spec.js
Exit with error status on test:each
Execute travis command using bundle exec
Upgrade rake
Lock sinatra version
Upgrade haml
Upgrade newrelic_rpm
Upgrade pg
Upgrade pony
Upgrade puma
Upgrade rouge
Upgrade minitest