Remove codecov (#3871)

.circleci/unittest/linux/scripts/environment.yml

@@ -6,7 +6,6 @@ channels:
 dependencies:
   - pytest
   - pytest-cov
-  - codecov
   - pip
   - libpng
   # NOTE: Pinned to fix issues with size_t on Windows

.circleci/unittest/linux/scripts/post_process.sh

@@ -4,5 +4,3 @@ set -e
 
 eval "$(./conda/bin/conda shell.bash hook)"
 conda activate ./env
-
-codecov

.circleci/unittest/windows/scripts/environment.yml

@@ -6,7 +6,6 @@ channels:
 dependencies:
   - pytest
   - pytest-cov
-  - codecov
   - pip
   - libpng
   # NOTE: Pinned to fix issues with size_t on Windows

.circleci/unittest/windows/scripts/post_process.sh

@@ -4,5 +4,3 @@ set -e
 
 eval "$(./conda/Scripts/conda.exe 'shell.bash' 'hook')"
 conda activate ./env
-
-codecov

README.rst

 torchvision
 ===========
 
-.. image:: https://codecov.io/gh/pytorch/vision/branch/master/graph/badge.svg
-    :target: https://codecov.io/gh/pytorch/vision
-
 .. image:: https://pepy.tech/badge/torchvision
     :target: https://pepy.tech/project/torchvision