Include link to Rubular

Author: pjb3

01_command_line_git_ruby/ruby_basics.html

@@ -646,7 +646,8 @@
 
 Regular Expressions can get insanely complex. For an example, look at this [regular expression for validating an email address](http://stackoverflow.com/a/719543).
 
-To learn more about Regular Expressions, check out the [Ruby for Newbies: Regular Expressions](http://code.tutsplus.com/tutorials/ruby-for-newbies-regular-expressions--net-19812) tutorial.
+To learn more about Regular Expressions, check out [Rubular](http://www.rubular.com/), especial the cheat sheat at the bottom.
+You should try to commit those parts of regular expressions to memory.
 
 
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