Improve specs and docs for String module
Improve specs and docs for String module

joshprice/elixir,kelvinst/elixir,ggcampinho/elixir,beedub/elixir,pedrosnk/elixir,antipax/elixir,pedrosnk/elixir,kimshrier/elixir,kelvinst/elixir,beedub/elixir,gfvcastro/elixir,antipax/elixir,elixir-lang/elixir,lexmag/elixir,ggcampinho/elixir,michalmuskala/elixir,gfvcastro/elixir,kimshrier/elixir,lexmag/elixir