Add composer.lock to gitignore
Add vendors to gitignore
Remove a var_dump() call
Reformat composer.json
Fix the project type
Reformat README
Change the installation version format
Fix the installation command
Simplify the PHPUnit running command

PHPUnit will find phpunit.xml or phpunit.xml.dist automatically and run the specified suite
Fix capitalization
Use the tilde version format to install the Symfony Config component
Make PHPUnit a dev dependency
Merge pull request #4 from elnur/various-fixes

Various fixes