Fix capitalization in AwsVpcConfiguration

[akarve]

Switch to the AWS documented capitalization to avoid the following error (and related):

E3002 Invalid Property Resources/BulkScannerService/Properties/NetworkConfiguration/AwsvpcConfiguration

which appears in cfn-lint==0.36.1

I attempted to run the unit tests but in vera case bottomed out with

======================================================================
ERROR: test_CustomResource (tests.test_examples.TestExamples)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/karve/code/troposphere/.eggs/awacs-0.9.8-py3.6.egg/tests/test_examples.py", line 21, in test_file
    exec(code)
  File "examples/CustomResource.py", line 5, in <module>
    class CustomPlacementGroup(AWSCustomObject):
  File "examples/CustomResource.py", line 9, in CustomPlacementGroup
    'ServiceToken': (basestring, True),
NameError: name 'basestring' is not defined

----------------------------------------------------------------------
Ran 107 tests in 0.302s

and didn't see documentation on overcoming the same.

[markpeek]

Thanks!

[akarve]

Sure thing, just note that the backend issue is still resolving aws-cloudformation/cfn-lint#1706

[michael-k]

I attempted to run the unit tests but in vera case bottomed out with

You have to invoke them with python setup.py test or run 2to3 manually on the codebase.

troposphere/setup.py

Line 93 in 1ca9e8c

use_2to3=True,

[PatMyron]

This property was accidentally uppercased during the migration of AWS::ECS::Service to the CloudFormation Registry in Resource Specification 18.4.0 and reverted in 18.6.0. It should probably be kept lowercase