Travis fix

Fixed title underline.

Author: merorafael

reference/forms/types/entity.rst

@@ -179,7 +179,7 @@ If specified, this entity manager will be used to load the choices
 instead of the ``default`` entity manager.
 
 choice_translation_domain
-~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~
 
 .. versionadded:: 2.7
     The ``choice_translation_domain`` option was introduced in Symfony 2.7.
@@ -189,7 +189,7 @@ choice_translation_domain
 This option determines whether the translation of the data obtained will be informed domain ``translation_domain``.
 
 translation_domain
-~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~
 
 .. versionadded:: 2.7
     The ``translation_domain`` option was introduced in Symfony 2.7.