[#293] Update .gitignore rules

- Discovered on installing PHPUnit to run tests that .gitignore was not setup to
  ignore composer.lock, nor the files installed in the bin/ directory.

.gitignore

@@ -7,3 +7,6 @@ tests/Zend/OpenId/_files/*
 tests/Zend/Translate/Adapter/_files/zend_cache---internal-metadatas---testid
 tests/Zend/Translate/Adapter/_files/zend_cache---testid
 vendor/*
+composer.lock
+bin/dbunit
+bin/phpunit