Added heatmap layer type.

src/components/layers/LayerEditor.jsx

@@ -138,7 +138,7 @@ export default class LayerEditor extends React.Component {
           onChange={v => this.changeProperty(null, 'source', v)}
         />
         }
-        {this.props.layer.type !== 'raster' && this.props.layer.type !== 'background' && this.props.layer.type !== 'hillshade' &&
+        {['background', 'raster', 'hillshade', 'heatmap'].indexOf(this.state.type) < 0 &&
         <LayerSourceLayerBlock
           sourceLayerIds={sourceLayerIds}
           value={this.props.layer['source-layer']}

src/components/layers/LayerTypeBlock.jsx

@@ -23,6 +23,7 @@ class LayerTypeBlock extends React.Component {
           ['circle', 'Circle'],
           ['fill-extrusion', 'Fill Extrusion'],
           ['hillshade', 'Hillshade'],
+          ['heatmap', 'Heatmap'],
         ]}
         onChange={this.props.onChange}
         value={this.props.value}