Add missing type definitions

packages/website/ts/components/relayer_index/relayer_grid_tile.tsx

@@ -109,14 +109,14 @@ class ImgWithFallback extends React.Component<ImgWithFallbackProps, ImgWithFallb
             imageLoadFailed: false,
         };
     }
-    public render() {
+    public render(): React.ReactNode {
         if (this.state.imageLoadFailed || _.isUndefined(this.props.src)) {
             return <img src={this.props.fallbackSrc} style={this.props.style} />;
         } else {
             return <img src={this.props.src} onError={this._onError.bind(this)} style={this.props.style} />;
         }
     }
-    private _onError() {
+    private _onError(): void {
         this.setState({
             imageLoadFailed: true,
         });

packages/website/ts/components/relayer_index/relayer_index.tsx

@@ -48,14 +48,14 @@ export class RelayerIndex extends React.Component<RelayerIndexProps, RelayerInde
             error: undefined,
         };
     }
-    public componentWillMount() {
+    public componentWillMount(): void {
         // tslint:disable-next-line:no-floating-promises
         this._fetchRelayerInfosAsync();
     }
-    public componentWillUnmount() {
+    public componentWillUnmount(): void {
         this._isUnmounted = true;
     }
-    public render() {
+    public render(): React.ReactNode {
         const readyToRender = _.isUndefined(this.state.error) && !_.isUndefined(this.state.relayerInfos);
         if (!readyToRender) {
             return (

packages/website/ts/components/relayer_index/relayer_top_tokens.tsx

@@ -41,6 +41,6 @@ export const TopTokens: React.StatelessComponent<TopTokensProps> = (props: TopTo
     );
 };
 
-function tokenLinkFromToken(tokenInfo: WebsiteBackendTokenInfo, networkId: number) {
+function tokenLinkFromToken(tokenInfo: WebsiteBackendTokenInfo, networkId: number): string {
     return sharedUtils.getEtherScanLinkIfExists(tokenInfo.address, networkId, EtherscanLinkSuffixes.Address);
 }