feat: add withStyles HOC (#77)

- This HOC allows styles to be injected without `ThemeProvider`

src/withStyles.tsx

@@ -0,0 +1,20 @@
+import hoistNonReactStatic from 'hoist-non-react-statics';
+import * as React from 'react';
+
+const withStyles = (styles: object) => (WrappedComponent: any): any => {
+  const displayName =
+    WrappedComponent.displayName || WrappedComponent.name || 'Component';
+
+  class WithStyles extends React.Component {
+    public render() {
+      return <WrappedComponent {...this.props} wrappedStyles={styles} />;
+    }
+  }
+
+  (WithStyles as any).displayName = `WithStyles(${displayName})`;
+  hoistNonReactStatic(WithStyles, WrappedComponent);
+
+  return WithStyles;
+};
+
+export default withStyles;