Don't lowercase `NodeElement::getTagName` because it's always lowercased

Closes #55
Renaming `Radio` element to `RadioButton` for clarity

Closes #50
Adding `Abstract` prefix to some of abstract classes
Renaming test classes to match renamed classes with `Abstract` prefix
Merge pull request #44 from aik099/44-rename-abstract-classes-to-start-with-abstract-word

Rename abstract classes to start with "Abstract" word
Fixing installation instructions

Fixing installation instructions to match ones from the website
Use latest stable Mockery version
Using latest `paratest` in hopes that I won't have 50% coverage drop
Don't let Scrutinizer connection issues result in 20 minute long builds
Removing majority of PHPDoc's from test suite
Merge pull request #54 from aik099/54-remove-phpdoc-in-test-php-files

Remove PHPDoc in Test.php files
Cache found elements inside the locator