HHVM is required to pass, minor fixes

.travis.yml

@@ -20,8 +20,4 @@ script:
 
 after_script:
     - wget https://scrutinizer-ci.com/ocular.phar
-    - php ocular.phar code-coverage:upload --format=php-clover build/logs/clover.xml
-
-matrix:
-  allow_failures:
-    - php: hhvm
+    - php ocular.phar code-coverage:upload --format=php-clover build/logs/clover.xml

classes/connection_manager.php

@@ -64,7 +64,7 @@ final class Connection_Manager {
 	 * Make sure serialize/deseriaze doesn't work
 	 * @throws DomainException
 	 */
-	private function __wakup()
+	private function __wakeup()
 	{
 		throw new DomainException("Can't unserialize singleton");
 	}

classes/query_builder.php

@@ -1408,7 +1408,7 @@ class Query_Builder implements Query_Builder_Interface {
 	 *
 	 * @param string $type
 	 * @param string $table
-	 * @return $string
+	 * @return string
 	 */
 	protected function _compile_type($type='', $table='')
 	{