Simplify pattern and stop non-numeric characters being returned

Author: rastating

lib/wpxf/wordpress/fingerprint.rb

@@ -79,7 +79,7 @@ def check_version_from_custom_file(url, regex, fixed = nil, introduced = nil)
 
   private
 
-  WORDPRESS_VERSION_PATTERN = '([^\r\n"\']+\.[^\r\n"\']+)'
+  WORDPRESS_VERSION_PATTERN = '(\d+\.\d+(?:\.\d+)*)'
 
   WORDPRESS_GENERATOR_VERSION_PATTERN = %r{<meta\sname="generator"\s
     content="WordPress\s#{WORDPRESS_VERSION_PATTERN}"\s\/>}xi

spec/wordpress/fingerprint_spec.rb

@@ -36,11 +36,11 @@
 
   describe '#wordpress_version' do
     let(:body) do
-      '<meta name="generator" content="WordPress 4.0" />'
+      '<meta name="generator" content="WordPress 4.7.1" />'
     end
 
     it 'returns the WordPress version number' do
-      expect(subject.wordpress_version).to eq Gem::Version.new('4.0')
+      expect(subject.wordpress_version).to eq Gem::Version.new('4.7.1')
     end
   end