Direnv: Update to 0.1.72

Closes Homebrew/homebrew#7741.

Signed-off-by: Charlie Sharpsteen <source@sharpsteen.net>

Formula/direnv.rb

@@ -2,8 +2,8 @@ require 'formula'
 
 class Direnv < Formula
   homepage 'https://github.com/zimbatm/direnv'
-  url 'https://github.com/zimbatm/direnv/tarball/v0.1.65'
-  md5 'fbcedf4ddd5ae2e2fa1760a4ef4280c6'
+  url 'https://github.com/zimbatm/direnv/tarball/v0.1.72'
+  md5 '34fecdff4bc6a5cbe4890ad14e5f3438'
 
   head 'https://github.com/zimbatm/direnv.git'
 
@@ -14,4 +14,21 @@ class Direnv < Formula
     bin.mkpath
     ln_s libexec+'direnv', bin+'direnv'
   end
+
+  def caveats
+    <<-EOS.undent
+    One last step.
+
+    At the END of your ~/.bashrc or ~/.zshrc, add the following line:
+
+      eval `direnv hook $0`
+
+    I mean, AFTER rvm, git-prompt and friends :)
+
+    Reload your shell, done.
+
+    See the wiki for docs and examples:
+      https://github.com/zimbatm/direnv/wiki/
+    EOS
+  end
 end