Allow inline styles (#29288)

types/react-spinkit/index.d.ts

@@ -33,6 +33,8 @@ declare namespace spinner {
          * for circle or folding-cube); this can either be a hex value or a color word
          */
         color?: string;
+
+        style?: React.CSSProperties
 	}
 
 	export interface Spinner extends React.ComponentClass<SpinnerProps> {

types/react-spinkit/react-spinkit-tests.tsx

@@ -49,4 +49,5 @@ const spinners = [
     <Spinner name="wordpress" color="green" />,
     <Spinner name="wordpress" overrideSpinnerClassName="my-class-to-override" />,
     <Spinner name="wordpress" className="my-class" />,
+    <Spinner name="wordpress" style={{ margin: '0 auto' }} />,
 ];