Minor linting fixups - 2022-08-12 (ansible-collections#1408)

Minor linting fixups - 2022-08-12

SUMMARY
Various linting and unit test fixups

unused variables
overly broad Exception catching (highlighted some broken tests)
removes direct use of unittest in favour of pytest (see also ansible-collections#961)
cleans up skipping of tests when botocore/boto3 aren't installed
passes error message from VPNConnectionException into its super to make testing easier, should never be directly exposed to the user

Removes tests for 3 modules which now have integration tests, they're either recording based (fragile)or test things which are separately tested in the integration tests.

lambda
s3_bucket_notifications
route53_zone

ISSUE TYPE

Feature Pull Request

COMPONENT NAME
plugins/modules/ec2_vpc_vpn.py
tests/unit
ADDITIONAL INFORMATION

Reviewed-by: Alina Buzachis <None>

This commit was initially merged in https://github.com/ansible-collections/community.aws
See: ansible-collections/community.aws@8b4afa9

plugins/modules/lambda_event.py

@@ -63,7 +63,7 @@
       enabled:
         description:
           -  Indicates whether AWS Lambda should begin polling or readin from the event source.
-        default: true.
+        default: true
         type: bool
       batch_size:
         description: