Show lint diff with color (#2102)

Summary:
*Before*
<img width="1094" alt="Screen Shot 2021-12-24 at 12 34 14 PM" src="https://user-images.githubusercontent.com/855818/147367213-b1e539c1-6e06-4e9b-aaf4-0458c502379b.png">

*After*

https://app.circleci.com/pipelines/github/pytorch/audio/8870/workflows/0445f1ac-ad48-412f-8045-2400d0cef4f4/jobs/482060

<img width="1096" alt="Screen Shot 2021-12-24 at 12 33 32 PM" src="https://user-images.githubusercontent.com/855818/147367210-a9b759bb-f992-4dc1-9359-0ec3912b3070.png">

Pull Request resolved: https://github.com/pytorch/audio/pull/2102

Reviewed By: carolineechen

Differential Revision: D33311253

Pulled By: mthrok

fbshipit-source-id: 6944921a8be58a2062b66a7dfd2c7ffe8c0866c3

.circleci/config.yml

@@ -129,7 +129,7 @@ jobs:
       - run:
           name: Required lint modifications
           when: always
-          command: git --no-pager diff
+          command: git --no-pager diff --color=always
 
   download_third_parties_nix:
     docker:

.circleci/config.yml.in

@@ -129,7 +129,7 @@ jobs:
       - run:
           name: Required lint modifications
           when: always
-          command: git --no-pager diff
+          command: git --no-pager diff --color=always
 
   download_third_parties_nix:
     docker: