Fix javivelasco#15

Author: javivelasco

src/components/themr.js

@@ -94,14 +94,11 @@ export default (componentName, localTheme, options = {}) => (ThemedComponent) =>
   }
 }
 
-function themeable(style = {}, theme) {
+export function themeable(style = {}, theme) {
   if (!theme) return style
   return Object.keys(theme).reduce((result, key) => (
-    Object.assign(result, { [key]:
-       style[key] && theme[key].indexOf(style[key]) === -1
-       ? `${style[key]} ${theme[key]}`
-       : theme[key] || style[key]
-    })), Object.assign({}, style))
+    Object.assign(result, { [key]: `${style[key]} ${theme[key]}` })
+  ), Object.assign({}, style))
 }
 
 function validateComposeOption(composeTheme) {