With this review request I fixed a lot of style issues. This includes:

- Making sure that includes are properly alphabetized;

- Got rid of escaped characters by making the string double-quoted;

- Renamed variables so they are more consistent;

- Aligned strings;

- Removed outer parenthesis where they are not needed on tuples;

- Improved some of the user-visible descriptions;

- Added a docstring for SecurityCheckRunner;

- Fixed blank lines;

- Fixed URLs;

- Fixed indentation in the template;

- Moved HTML styling into CSS tags.
In terms of actual functionality, I changed the ExecutableCodeCheck test to be able to fail on multiple file types. Before it would end the test on the first failed file type and return that to the user. Now it will return a list of each file type that fails.
I've also included some screenshots to show what various success/failure statuses look like.

Ran through all tests and they succeeded when they should and also failed when they should when I introduced failure conditions.