Added CodeBuild flag 'badge_enabled'

[vpadronblanco]

Closes #2836

• Added 'badge_enabled' resource property
• Added 'badge_url' resource property to be visible for attribute referencing
• Added properties in the documentation
• Added acceptance test

Test output:
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -run=TestAccAWSCodeBuildProject_buildBatchUrlValidation -timeout 120m
=== RUN TestAccAWSCodeBuildProject_buildBatchUrlValidation
--- PASS: TestAccAWSCodeBuildProject_buildBatchUrlValidation (25.30s)
PASS
ok github.com/terraform-providers/terraform-provider-aws/aws 25.341s

[vpadronblanco]

I resolved the merge conflict, turns out I did not properly update my branch before committing to master. While merging, I kept all the changes from the upstream repository. But, to make sure everything is in order, I am trying to run the test Brian added called "testAccAWSCodeBuildProjectConfig_sourceAuth". This is the error produced:

==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -run=TestAccAWSCodeBuildProject_sourceAuth -timeout 120m
=== RUN TestAccAWSCodeBuildProject_sourceAuth
--- FAIL: TestAccAWSCodeBuildProject_sourceAuth (6.07s)
testing.go:513: Step 1 error: Error applying: 1 error(s) occurred:

	* aws_codebuild_project.foo: 1 error(s) occurred:
	
	* aws_codebuild_project.foo: [ERROR] Error creating CodeBuild project: InvalidInputException: No Access token found, please visit AWS CodeBuild console to connect to GitHub
		status code: 400, request id: f996a104-110f-11e8-b8bb-8947dbd30aa0
testing.go:573: Error destroying resource! WARNING: Dangling resources
	may exist. The full state and error is shown below.
	
	Error: Check failed: Default error in CodeBuild Test
	
	State: <no state>

FAIL
exit status 1
FAIL github.com/terraform-providers/terraform-provider-aws/aws 6.118s
make: *** [testacc] Error 1

[vpadronblanco]

I will close this pull request since I referenced my master branch and I have conflicts with merges from upstream

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

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