cleanup Lens repo with tighter linting

Signed-off-by: Sebastian Malton <smalton@mirantis.com>

dashboard/client/components/stepper/index.ts

@@ -1 +1 @@
-export * from './stepper'
+export * from './stepper';

dashboard/client/components/stepper/stepper.tsx

@@ -12,7 +12,7 @@ interface Step {
 }
 
 export class Stepper extends React.Component<Props, {}> {
-  render() {
+  render(): JSX.Element {
     const { className, steps, ...props } = this.props;
     const stepsCount = steps.length;
     let { step } = this.props;