Use css class in favor of inline styles

ui/src/data_explorer/components/DatabaseList.js

@@ -64,7 +64,7 @@ const DatabaseList = React.createClass({
     const {query, onChooseNamespace} = this.props
 
     return (
-      <div className="query-builder--column" style={{flex: '1 0 0'}}>
+      <div className="query-builder--column query-builder--column-db">
         <div className="query-builder--heading">Databases</div>
         <div className="query-builder--list">
           {this.state.namespaces.map(namespace => {

ui/src/style/components/query-builder.scss

@@ -15,6 +15,9 @@
   flex-direction: column;
   flex: 2 0 0;
 }
+.query-builder--column-db {
+  flex: 1 0 0;
+}
 .query-builder--heading {
   @include no-user-select();
   width: 100%;