Add an error boundary component to catch errors.

src/components/ErrorBoundary.tsx

@@ -0,0 +1,37 @@
+import * as React from 'react';
+
+class ErrorBoundary extends React.Component {
+  state: {
+    error?: Error;
+  };
+
+  constructor(props: any) {
+    super(props);
+    this.state = { };
+  }
+
+  componentDidCatch(error: Error, info: any) {
+    this.setState({ error });
+  }
+
+  render() {
+    if (this.state.error) {
+      return (
+        <div>
+          <h2>Something went wrong!</h2>
+          <pre>
+            {this.state.error.message}
+          </pre>
+
+          <h3>Stack trace:</h3>
+          <pre>
+            {this.state.error.stack}
+          </pre>
+        </div>
+      );
+    }
+    return this.props.children;
+  }
+}
+
+export default ErrorBoundary;