Renamed :global atom for defdelegate deprecation in elixir 1.3

[deadkarma]

I've been using this fork on a production site ( using elixir 1.2.6 ) for about a week now and so far so good :)

[coveralls]

Coverage remained the same at 100.0% when pulling 644ca3a on deadkarma:defdelegate_fix into 3fed1c0 on Zensavona:master.

[Zensavona]

Thanks for this @deadkarma, had a look and merged. I also just added a 1.3.x target for travis tests so these things get caught. I'll cut a release when I get home from uni :)