Remove last mentions of 'RuboCop-RSpec'

Author: pirj

README.md

@@ -71,7 +71,7 @@ rubocop-rspec is available on Code Climate as part of the rubocop engine. [Learn
 
 ## Documentation
 
-You can read more about RuboCop-RSpec in its [official manual](https://docs.rubocop.org/rubocop-rspec).
+You can read more about RuboCop RSpec in its [official manual](https://docs.rubocop.org/rubocop-rspec).
 
 ## The Cops
 

lib/rubocop/rspec/node.rb

@@ -2,7 +2,7 @@
 
 module RuboCop
   module RSpec
-    # RuboCop-RSpec specific extensions of RuboCop::AST::Node
+    # RuboCop RSpec specific extensions of RuboCop::AST::Node
     module Node
       # In various cops we want to regard const as literal althought it's not
       # strictly literal.