Add button tooltips

src/App.js

@@ -294,6 +294,7 @@ class App extends React.Component {
               onClick={this.acceptCookies}
               icon={<CheckRoundedIcon/>}
               className="button--round"
+              title="Accept"
             ></Button>
           </div>
         </Router>

src/GroupPage.js

@@ -382,6 +382,7 @@ export default withRouter(class GroupPage extends Component {
 										onClick={this.showDeleteGroup}
 										icon={<DeleteRoundedIcon />}
 										className="button--round"
+										title="Delete group"
 									></Button>
 								}
 							</div>
@@ -425,6 +426,7 @@ export default withRouter(class GroupPage extends Component {
 															icon={<DeleteRoundedIcon />}
 															loading={this.state.sets[setId].loading}
 															disabled={this.state.sets[setId].loading}
+															title="Remove set"
 														></Button>
 													}
 												</div>

src/History.js

@@ -232,6 +232,7 @@ export default class History extends Component {
 																	className="button--no-background"
 																	onClick={() => this.deleteProgress(progressItem.id)}
 																	icon={<DeleteRoundedIcon />}
+																	title="Delete"
 																></Button>
 															</p>
 														</div>

src/LoggedInHome.js

@@ -449,6 +449,7 @@ export default withRouter(class LoggedInHome extends React.Component {
 													icon={<DeleteRoundedIcon />}
 													disabled={this.state.pendingDeletions[progressItem.id] === true}
 													loading={this.state.pendingDeletions[progressItem.id] === true}
+													title="Delete"
 												></Button>
 											</p>
 										</div>

src/SetPage.js

@@ -355,13 +355,15 @@ export default withRouter(class SetPage extends React.Component {
 										loading={this.state.loading}
 										onClick={this.showTestStart}
 										icon={<PlayArrowRoundedIcon />}
-											disabled={!this.state.canStartTest}
+										disabled={!this.state.canStartTest}
-											className="button--round"
+										className="button--round"
+										title="Start test"
 									></Button>
 									<Button
 										onClick={() => this.showAddSetToGroup()}
 										icon={<GroupAddRoundedIcon />}
-											className="button--round"
+										className="button--round"
+										title="Add to group"
 									></Button>
 									{
 										this.state.set.owner === this.state.user.uid &&
@@ -369,6 +371,7 @@ export default withRouter(class SetPage extends React.Component {
 											to={`/sets/${this.props.match.params.setId}/edit`}
 											icon={<EditRoundedIcon />}
 											className="button--round"
+											title="Edit"
 										></LinkButton>
 									}
 									{
@@ -377,6 +380,7 @@ export default withRouter(class SetPage extends React.Component {
 											onClick={() => this.showDeleteSet()}
 											icon={<DeleteRoundedIcon />}
 											className="button--round"
+											title="Delete"
 										></Button>
 									}
 								</div>
@@ -484,8 +488,8 @@ export default withRouter(class SetPage extends React.Component {
 								onSliderChange={this.changeSliderValue}
 								switchLanguage={this.state.switchLanguage}
 								handleSwitchLanguageChange={this.handleSwitchLanguageChange}
-									loading={this.state.loading}
+								loading={this.state.loading}
-									disabled={!this.state.canStartTest}
+								disabled={!this.state.canStartTest}
 							/>
 						}
 						{