Fix lexing of brackets in Velocity lexer (#1605)

The Velocity lexer includes a rule that incorrectly spells the `:push`
magic state as `:push!`. This causes an error when lexing brackets
(which match this rule). This commit fixes that mistake.

lib/rouge/lexers/velocity.rb

@@ -63,7 +63,7 @@ class Velocity < TemplateLexer
         rule %r/0[xX][0-9a-fA-F]+[Ll]?/, Num::Hex
         rule %r/\b[0-9]+\b/, Num::Integer
         rule %r/(true|false|null)\b/, Keyword::Constant
-        rule %r/[(\[]/, Punctuation, :push!
+        rule %r/[(\[]/, Punctuation, :push
         rule %r/[)\]}]/, Punctuation, :pop!
       end
     end

spec/visual/samples/velocity

@@ -20,6 +20,7 @@
 </table>
 #end
 #set( $monkey.Say = ["Not", $my, "fault", 10, false, null] ) ## ArrayList
+#set( $result = $foo($bar[$baz]) )
 ${mudSlinger}
 ${customer.Address}
 ${purchase.getTotal(true)}