Upgrade less to 3.9.0 (from 3.8.1)

Author: bdukes

package.json

@@ -51,7 +51,7 @@
     "knockout-postbox": "0.6.0",
     "knockout-sortable": "1.1.0",
     "knockout.validation": "2.0.3",
-    "less": "3.8.1",
+    "less": "3.9.0",
     "lie": "3.3.0",
     "lightbox2": "2.10.0",
     "moment": "2.22.2",

yarn.lock

@@ -2902,10 +2902,10 @@ latest-version@^3.0.0:
   dependencies:
     package-json "^4.0.0"
 
-less@3.8.1:
-  version "3.8.1"
-  resolved "https://registry.yarnpkg.com/less/-/less-3.8.1.tgz#f31758598ef5a1930dd4caefa9e4340641e71e1d"
-  integrity sha512-8HFGuWmL3FhQR0aH89escFNBQH/nEiYPP2ltDFdQw2chE28Yx2E3lhAIq9Y2saYwLSwa699s4dBVEfCY8Drf7Q==
+less@3.9.0:
+  version "3.9.0"
+  resolved "https://registry.yarnpkg.com/less/-/less-3.9.0.tgz#b7511c43f37cf57dc87dffd9883ec121289b1474"
+  integrity sha512-31CmtPEZraNUtuUREYjSqRkeETFdyEHSEPAGq4erDlUXtda7pzNmctdljdIagSb589d/qXGWiiP31R5JVf+v0w==
   dependencies:
     clone "^2.1.2"
   optionalDependencies: