resolve error message from DetailPageHeader test (#356)
resolve error message from DetailPageHeader test (#356)

* removed unneeded extra shallow rendering in individual test

carbon-design-system/carbon-components,hellobrian/carbon-components-react,carbon-design-system/carbon-components-react,carbon-design-system/carbon-components-react,carbon-design-system/carbon-components,joshblack/carbon-components-react,jzhang300/carbon-components-react,carbon-design-system/carbon-components,joshblack/carbon-components-react,hellobrian/carbon-components-react