Fix deprecated test cases that use "package" to use "packages"

This is a follow-on issue to PR: https://github.com/apache/incubator-openwhisk-wskdeploy/pull/743

which removed support for the deprecated "package" key from all top-level schema.

This issue indicates and track which unit tests and integration tests that are not disabled and need re-coding (or affirm deletion as no longer needed) on one or more PRs:

Unit tests:
- **deployementreader_test.go**: TestDeploymentReader_bindTrigger_package (i.e., ../tests/dat/deployment-deploymentreader-test-package.yml)
- **whisk_client_test.go**: TestNewWhiskConfigManifestFile (i.e., ../tests/dat/manifest_validate_credentials.yaml)
- **manifest_parser_test.go**: TestUnmarshalForHelloWithParams
- **manifest_parser_test.go**: TestUnmarshalForMissingPackage
- **manifest_parser_test.go**: TestComposeActionsForInvalidWebActions
- **manifest_parser_test.go**: TestComposePackage
- **manifest_parser_test.go**: TestComposeTriggers
- **manifest_parser_test.go**: TestComposeRules
- **manifest_parser_test.go**: TestComposeDependencies
- **manifest_parser_test.go**: TestBadYAMLInvalidPackageKeyInManifest
- **yamlparser_test.go**: TestComposeWskTrigger
- **yamlparser_test.go**: TestComposeWskRule
- **dependency_test.go**: TestDependency

Integration tests:
- tests/src/integration/validateSequencesCreation/validateSequencesCreation_test.go

Note: I will try to fix a large # in manifest_parser_test.go as they all should involve fixing a common function that checks the initial schema in a similar way. If so, I will note that here once completed.