Fix js warnings (#2693)

* react: using prop-types package to fix deprecated React.PropTypes property warning

https://facebook.github.io/react/warnings/dont-call-proptypes.html

* removing babel devDependency because has been deprecated in favor of babel-cli

this fixes a warning during `npm install`:
```
npm WARN deprecated babel@6.23.0:
In 6.x, the babel package has been deprecated in favor of babel-cli.
Check https://opencollective.com/babel to support the Babel maintainers
```

* js: setting ExploreActionButtons.queryEndpoint PropType as required

because it's required in the child component DisplayQueryButton

* js(tests): using object in expandedSlices prop type of SliceCell tests

* js(tests): adding required props to SqlEditor mockedProps

* js(tests): adding required prop editorHeight to TabbedSqlEditors mockedProps

* js: removing unused moments dependency

superset/assets/visualizations/filter_box.jsx

@@ -1,6 +1,7 @@
 // JS
 import d3 from 'd3';
 import React from 'react';
+import PropTypes from 'prop-types';
 import ReactDOM from 'react-dom';
 import Select from 'react-select';
 import { Button } from 'react-bootstrap';
@@ -10,11 +11,11 @@ import { TIME_CHOICES } from './constants';
 import './filter_box.css';
 
 const propTypes = {
-  origSelectedValues: React.PropTypes.object,
-  instantFiltering: React.PropTypes.bool,
-  filtersChoices: React.PropTypes.object,
-  onChange: React.PropTypes.func,
-  showDateFilter: React.PropTypes.bool,
+  origSelectedValues: PropTypes.object,
+  instantFiltering: PropTypes.bool,
+  filtersChoices: PropTypes.object,
+  onChange: PropTypes.func,
+  showDateFilter: PropTypes.bool,
 };
 
 const defaultProps = {

superset/assets/visualizations/mapbox.jsx

@@ -1,6 +1,7 @@
 /* eslint-disable no-param-reassign */
 import d3 from 'd3';
 import React from 'react';
+import PropTypes from 'prop-types';
 import ReactDOM from 'react-dom';
 import MapGL from 'react-map-gl';
 import ScatterPlotOverlay from 'react-map-gl/dist/overlays/scatterplot.react';
@@ -256,20 +257,20 @@ class MapboxViz extends React.Component {
   }
 }
 MapboxViz.propTypes = {
-  aggregatorName: React.PropTypes.string,
-  clusterer: React.PropTypes.object,
-  globalOpacity: React.PropTypes.number,
-  mapStyle: React.PropTypes.string,
-  mapboxApiKey: React.PropTypes.string,
-  pointRadius: React.PropTypes.number,
-  pointRadiusUnit: React.PropTypes.string,
-  renderWhileDragging: React.PropTypes.bool,
-  rgb: React.PropTypes.array,
-  sliceHeight: React.PropTypes.number,
-  sliceWidth: React.PropTypes.number,
-  viewportLatitude: React.PropTypes.number,
-  viewportLongitude: React.PropTypes.number,
-  viewportZoom: React.PropTypes.number,
+  aggregatorName: PropTypes.string,
+  clusterer: PropTypes.object,
+  globalOpacity: PropTypes.number,
+  mapStyle: PropTypes.string,
+  mapboxApiKey: PropTypes.string,
+  pointRadius: PropTypes.number,
+  pointRadiusUnit: PropTypes.string,
+  renderWhileDragging: PropTypes.bool,
+  rgb: PropTypes.array,
+  sliceHeight: PropTypes.number,
+  sliceWidth: PropTypes.number,
+  viewportLatitude: PropTypes.number,
+  viewportLongitude: PropTypes.number,
+  viewportZoom: PropTypes.number,
 };
 
 function mapbox(slice, json) {