frontend: Some linting

frontend/src/App.js

@@ -2,7 +2,6 @@ import React from 'react'
 import {connect} from 'react-redux'
 import {Icon, Button} from 'semantic-ui-react'
 import {BrowserRouter as Router, Switch, Route, Link} from 'react-router-dom'
-import _ from 'lodash'
 
 import styles from './App.module.scss'
 import api from './api'
@@ -42,7 +41,7 @@ const App = connect((state) => ({login: state.login}))(function App({login}) {
                   <Link to="/feed">Feed</Link>
                 </li>
                 <li>
-                  <a href="https://openbikesensor.org/" target="_blank">
+                  <a href="https://openbikesensor.org/" target="_blank" rel="noreferrer">
                     About
                   </a>
                 </li>

frontend/src/pages/TrackPage/index.tsx

@@ -3,7 +3,7 @@ import {connect} from 'react-redux'
 import {Table, Checkbox, Segment, Dimmer, Grid, Loader, Header} from 'semantic-ui-react'
 import {useParams} from 'react-router-dom'
 import {concat, combineLatest, of, from, Subject} from 'rxjs'
-import {pluck, distinctUntilChanged, map, switchMap, startWith, sample} from 'rxjs/operators'
+import {pluck, distinctUntilChanged, map, switchMap, startWith} from 'rxjs/operators'
 import {useObservable} from 'rxjs-hooks'
 import Markdown from 'react-markdown'
 

frontend/src/query.ts

@@ -52,7 +52,7 @@ export function useQueryParam<T extends QueryValue>(
   convert: (t: T | null) => T | null = (x) => x
 ): [T, (newValue: T) => void] {
   const history = useHistory()
-  const _triggerReload = useLocation()
+  useLocation() // to trigger a reload when the url changes
   const {[name]: value = defaultValue} = (parseQuery(history.location.search) as unknown) as {
     [name: string]: T
   }