resolve credscan warnings

[christopheranderson]

Resolves following false alarms:

changelog.md(137,): error : SecretinFile : 
{{Searcher}}ConfigFile
{{Code}}See changelog.md line 137 for the code resulting in match
{{Info}}Found password, symmetric key or storage credential in source file.
{{Suggest}}Validate file contains secrets, remove, roll credential, and use approved store. For additional information on secret remediation see https://aka.ms/credscan 

test\unit\helper.spec.ts(17,): error : SecretinFile : 
{{Searcher}}ConfigFile
{{Code}}See helper.spec.ts line 17 for the code resulting in match
{{Info}}Found password, symmetric key or storage credential in source file.
{{Suggest}}Validate file contains secrets, remove, roll credential, and use approved store. For additional information on secret remediation see https://aka.ms/credscan 

test\unit\helper.spec.ts(21,): error : SecretinFile : 
{{Searcher}}ConfigFile
{{Code}}See helper.spec.ts line 21 for the code resulting in match
{{Info}}Found password, symmetric key or storage credential in source file.
{{Suggest}}Validate file contains secrets, remove, roll credential, and use approved store. For additional information on secret remediation see https://aka.ms/credscan