fix(OverflowMenuItem): use PropTypes module (#100)
fix(OverflowMenuItem): use PropTypes module (#100)

A recent change used the React PropTypes property instead of the React one.

Fixes #99
carbon-design-system/carbon-components,joshblack/carbon-components-react,carbon-design-system/carbon-components-react,hellobrian/carbon-components-react,jzhang300/carbon-components-react,joshblack/carbon-components-react,hellobrian/carbon-components-react,carbon-design-system/carbon-components,carbon-design-system/carbon-components,carbon-design-system/carbon-components-react