pyenv: remove non-Homebrew-specific caveats.

Formula/pyenv.rb

@@ -21,15 +21,6 @@ class Pyenv < Formula
     end
   end
 
-  def caveats; <<-EOS.undent
-    To use Homebrew's directories rather than ~/.pyenv add to your profile:
-      export PYENV_ROOT=#{var}/pyenv
-
-    To enable shims and autocompletion add to your profile:
-      if which pyenv > /dev/null; then eval "$(pyenv init -)"; fi
-    EOS
-  end
-
   test do
     shell_output("eval \"$(#{bin}/pyenv init -)\" && pyenv versions")
   end