fix(bannermessage) doesn't accept text wrapped in paragraph tag. (#315)

don't assume a naked string is passed through. body container is now div. if naked string is passed, wrap it in paragraph tag.

src/components/BannerMessage/BannerMessageBody.jsx

@@ -6,10 +6,11 @@ import React from 'react'
 
 const BannerMessageBody = props => {
   const { children, ...rest } = props
+  const content = typeof children === 'string' ? <p>{children}</p> : children
   return (
-    <p className='banner-message__body' {...rest}>
-      {children}
-    </p>
+    <div className='banner-message__body' {...rest}>
+      {content}
+    </div>
   )
 }