Fixed typos in Mix.Tasks.Test docs
Fixed typos in Mix.Tasks.Test docs

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