Fix missing source_code in LaTeX HTML.

STUD-565

cms/djangoapps/contentstore/features/html-editor.py

@@ -15,3 +15,14 @@ def i_created_blank_html_page(step):
 @step('I see only the HTML display name setting$')
 def i_see_only_the_html_display_name(step):
     world.verify_all_setting_entries([['Display Name', "Text", False]])
+
+
+@step('I have created an E-text Written in LaTeX$')
+def i_created_blank_html_page(step):
+    world.create_component_instance(
+        step,
+        '.large-html-icon',
+        'html',
+        '.xmodule_HtmlModule',
+        'latex_html.yaml'
+    )