Added a check for valid elements and attributes

Author: patrickschur

CHANGELOG.md

@@ -1,6 +1,10 @@
 # Change Log
 All notable changes to this project will be documented in this file.
 
+## [1.0.0] - 2017-03-16
+### Added
+- Check for valid elements and attributes
+
 ## [0.0.1] - 2017-03-14
 ### Added
 - Tests (Travis-CI and Codecov)

README.md

@@ -148,7 +148,7 @@ outputs:
 ```
 
 #### [TODO] Checklist:
-- [ ] Exists the attribute for the element?
+- [x] Exists the attribute for the element? (Find a better implementation of that!)
 - [ ] Is the given attribute value allowed for the specified attribute?
 - [ ] Is the element allowed in the current element?
 - [ ] Check the document for bad practices. For example duplicate id references.