Combine import and package rules in Java lexer (#1389)

The lexing that is performed for packages imported using the import 
keyword should be the same for the package keyword. This is consistent 
with the current behaviour in the Pygments lexer.

lib/rouge/lexers/java.rb

@@ -50,10 +50,9 @@ class Java < RegexLexer
         rule %r/@#{id}/, Name::Decorator
         rule %r/(?:#{declarations.join('|')})\b/, Keyword::Declaration
         rule %r/(?:#{types.join('|')})\b/, Keyword::Type
-        rule %r/package\b/, Keyword::Namespace
         rule %r/(?:true|false|null)\b/, Keyword::Constant
         rule %r/(?:class|interface)\b/, Keyword::Declaration, :class
-        rule %r/import\b/, Keyword::Namespace, :import
+        rule %r/(?:import|package)\b/, Keyword::Namespace, :import
         rule %r/"(\\\\|\\"|[^"])*"/, Str
         rule %r/'(?:\\.|[^\\]|\\u[0-9a-f]{4})'/, Str::Char
         rule %r/(\.)(#{id})/ do