Remove the word "Student" from the title.

At Stanford, we are required to refer to users as participants. Removed the word
Student from the progress certificate title. The word "Student" does not change when the
user context is changed.

lms/templates/courseware/progress.html

@@ -62,7 +62,7 @@ username = get_enterprise_learner_generic_name(request) or student.username
                 </div>
                 % endif
                 <h2 class="hd hd-2 progress-certificates-title">
-                    ${_("Course Progress for Student '{username}' ({email})").format(username=username, email=student.email)}
+                    ${_("Course Progress for '{username}' ({email})").format(username=username, email=student.email)}
                 </h2>
                 % if course_expiration_fragment:
                     ${HTML(course_expiration_fragment.content)}