Merge #1544

1544: Highlight mutable variables differently r=matklad a=viorina

![Screenshot from 2019-07-18 19-04-57](https://user-images.githubusercontent.com/6714973/61473539-3f5d3000-a98f-11e9-99ec-a4115b2ba66b.png)


Co-authored-by: Ekaterina Babshukova <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/editors/code/src/highlighting.ts b/editors/code/src/highlighting.ts
index 52a0bd4bb..f3ed66365 100644
--- a/editors/code/src/highlighting.ts
+++ b/editors/code/src/highlighting.ts
@@ -56,6 +56,7 @@ export class Highlighter {
             colorContrib('literal'),
             colorContrib('macro'),
             colorContrib('variable'),
+            colorContrib('variable.mut'),
             colorContrib('field'),
             colorContrib('module')
         ];