Use covdefaults to handle coveragerc

diff --git a/.coveragerc b/.coveragerc
deleted file mode 100644
index 7c592a9..0000000
--- a/.coveragerc
+++ /dev/null

@@ -1,29 +0,0 @@
-[run]
-branch = True
-source =
-    .
-omit =
-    .tox/*
-    /usr/*
-    setup.py
-
-[report]
-show_missing = True
-skip_covered = True
-exclude_lines =
-    # Have to re-enable the standard pragma
-    \#\s*pragma: no cover
-
-    # Don't complain if tests don't hit defensive assertion code:
-    ^\s*raise AssertionError\b
-    ^\s*raise NotImplementedError\b
-    ^\s*return NotImplemented\b
-    ^\s*raise$
-
-    # Don't complain if non-runnable code isn't run:
-    ^if __name__ == ['"]__main__['"]:$
-
-[html]
-directory = coverage-html
-
-# vim:ft=dosini

diff --git a/requirements-dev.txt b/requirements-dev.txt
index cf74d9f..67f6485 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt

@@ -1,6 +1,4 @@
--e .
-
+covdefaults
 coverage
-mock
 pre-commit
 pytest

diff --git a/setup.cfg b/setup.cfg
index c05ca0c..e6c488a 100644
--- a/setup.cfg
+++ b/setup.cfg

@@ -68,6 +68,9 @@
 [bdist_wheel]
 universal = True
 
+[coverage:run]
+plugins = covdefaults
+
 [mypy]
 check_untyped_defs = true
 disallow_any_generics = true

diff --git a/tests/detect_aws_credentials_test.py b/tests/detect_aws_credentials_test.py
index 41b7b0a..4f00744 100644
--- a/tests/detect_aws_credentials_test.py
+++ b/tests/detect_aws_credentials_test.py

@@ -1,5 +1,6 @@
+from unittest.mock import patch
+
 import pytest
-from mock import patch
 
 from pre_commit_hooks.detect_aws_credentials import get_aws_cred_files_from_env
 from pre_commit_hooks.detect_aws_credentials import get_aws_secrets_from_env