Add bang variants to from_erl and from_iso8601
Add bang variants to from_erl and from_iso8601

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