Remove code coverage visualization

Author: SbWereWolf

README.md

@@ -148,11 +148,6 @@ array (
 - [Pick your entry point](#pick-your-entry-point)
 - [Contacts](#contacts)
 
-## Code test coverage
-
-![Codecov graph](https://codecov.io/github/SbWereWolf/xml-navigator/graphs/tree.svg?token=Q0BQ2COFTC)
-
-
 ## Working examples
 
 ### Turn XML into arrays with custom keys