Fix my own typo in helpers.ex

Brand-new language, and I put a ding in it. Sorry about that. :-(

Congratulations on 1.0!
Merge pull request #2766 from billgathen/patch-2

Fix typo in helpers.ex
fix previous commit typo bug
Merge pull request #2767 from yol0/master

fix previous commit typo bug in bin/elixir
Fix a typo in IO.inspect’s doc
Fix a typo in Code.eval_file's doc
Merge pull request #2768 from budstein/patch-1

Fix a typo in Code.eval_file's doc
Fixed String doc link
Merge pull request #2770 from jwarwick/string_doc_typo

Fixed String doc link
Ensure chunk/4 is haltable
fix example sample.ex -> sample.eex
Merge pull request #2772 from pdericson/master

fix example sample.ex -> sample.eex
Do not require {ref, :done}, instead allow sync removal
Add U as ungreedy option, soft deprecate r
Allow U (upper case u) as an option for sigil_r
Fix a typo in Dict's docs
Load dependencies before deps.check compiles
Add tests for add_process_handler/2
default ports for WebSocket
Merge pull request #2776 from rbaier/uri-ws

Default ports for WebSocket