rename fill attribute

Summary:
We were using `fill={true}` as an attribute to make flexbox containers fill the entire available space.

However, `fill` is an HTML attribute (see: https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/fill) This caused warnings printed to the console.

This diff renames the attribute to `grow` with is also more in line with the Flexbox terminology.

Reviewed By: priteshrnandgaonkar

Differential Revision: D10488389

fbshipit-source-id: ed8553c6203cdf6df94d26c731164ecec4c9fbd2

src/chrome/PluginManager.js

@@ -343,7 +343,7 @@ class PluginManager extends PureComponent<Props, State> {
     );
     return (
       <Container>
-        <FlexColumn fill={true}>
+        <FlexColumn grow={true}>
           {this.state.restartRequired && (
             <RestartRequired onClick={this.relaunch}>
               <Glyph name="arrows-circle" size={12} color={colors.white} />
@@ -396,7 +396,7 @@ const SearchablePluginManager = Searchable(PluginManager);
 export default class extends PureComponent<{}> {
   render() {
     return (
-      <FlexColumn fill={true}>
+      <FlexColumn grow={true}>
         <SearchablePluginManager />
       </FlexColumn>
     );