Increasing Test Coverage of "Controller.go"

[stravid87]

Description

This work item is about increasing coverage of the controller.go file (currently @ 50% ). You will implement B&B testing on the functions listed in the task list.

Acceptance Criteria

Completion of the task list below

### Functions for You to B\&B Test
- [x] func ServeFileHandler(w http.ResponseWriter, r *http.Request, filePath string)
- [x] func ClientProfileHandler(w http.ResponseWriter, r *http.Request)
- [x] func UpdateDisplayNameHandler(w http.ResponseWriter, r *http.Request)

Notes:

You will NOT be testing func GetUsageStats(w http.ResponseWriter, r *http.Request)

[stravid87]

Great work. Let's let Huzaifa merge first. Then fix conflicts and then open your own PR