add doc strings and adjust entry point in pyproject toml

pyproject.toml

@@ -71,7 +71,7 @@ x = "awx_plugins.credentials.x.api:XPlugin"
 [project.entry-points."awx.credential_plugins"]  # pre-existing entry points group name
 x = "awx_plugins.credentials.x.api:XPlugin"
 # conjur = awx.main.credential_plugins.conjur:conjur_plugin
-aws_assumerole = awx_plugins.credentials.aws_assumerole:aws_assumerole_plugin
+"aws_assumerole = awx_plugins.credentials.aws_assumerole:aws_assumerole_plugin"
 
 [project.license]
 file = "LICENSE"

tests/credential_plugins_test.py

@@ -133,6 +133,9 @@ def test_hashivault_handle_auth_not_enough_args():
 
 
 def test_aws_assumerole_with_accesssecret():
+    '''
+    Test that the aws_assumerole_backend function call returns a token given the access_key and secret_key.
+    '''
     kwargs = {
         'access_key': 'my_access_key',
         'secret_key': 'my_secret_key',
@@ -166,6 +169,9 @@ def test_aws_assumerole_with_accesssecret():
 
 
 def test_aws_assumerole_with_arnonly():
+    '''
+    Test backend function with only the role ARN provided.
+    '''
     kwargs = {
         'role_arn': 'the_arn',
         'identifier': 'access_token',