Duplicate upper/lowercase weapon images

[grahams]

Describe the bug
The files in static/img/weapons/ are duplicated with Upper and lowercase filename versions:

warning: the following paths have collided (e.g. case-sensitive paths on
a case-insensitive filesystem) and only one from the same colliding
group is in the working tree:

  'static/img/weapons/AK47.png'                                                   
  'static/img/weapons/ak47.png'
  'static/img/weapons/AUG.png'
  'static/img/weapons/aug.png'
  'static/img/weapons/AWP.png'
  'static/img/weapons/awp.png'
  [..]

To Reproduce
Steps to reproduce the behavior:

1. View the files in static/img/weapons/

Expected behavior
While this is technically allowed, some filesystems (Windows, macOS) are case insensitive and this can cause unexpected behavior. Since the files seem identical I suspect this was not intentional.

Environment info:

• OS: macOS
• CSGO stats version: master