Upgrade dependencies

package.json

@@ -56,7 +56,7 @@
   "dependencies": {
     "css-selector-tokenizer": "^0.7.0",
     "generic-names": "^1.0.2",
-    "icss-utils": "^2.1.0",
+    "icss-utils": "^3.0.1",
     "postcss": "^6.0.2"
   },
   "devDependencies": {

test/test.js

@@ -675,7 +675,7 @@ test("save :import statemtents", () => {
       }
     `,
     expected: `
-      :import("~/lol.css") {
+      :import('~/lol.css') {
         foo: __foo
       }
     `

yarn.lock

@@ -1583,11 +1583,11 @@ iconv-lite@^0.4.17:
   version "0.4.18"
   resolved "https://registry.yarnpkg.com/iconv-lite/-/iconv-lite-0.4.18.tgz#23d8656b16aae6742ac29732ea8f0336a4789cf2"
 
-icss-utils@^2.1.0:
-  version "2.1.0"
-  resolved "https://registry.yarnpkg.com/icss-utils/-/icss-utils-2.1.0.tgz#83f0a0ec378bf3246178b6c2ad9136f135b1c962"
+icss-utils@^3.0.1:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/icss-utils/-/icss-utils-3.0.1.tgz#ee70d3ae8cac38c6be5ed91e851b27eed343ad0f"
   dependencies:
-    postcss "^6.0.1"
+    postcss "^6.0.2"
 
 ignore@^3.3.3:
   version "3.3.3"
@@ -2666,14 +2666,6 @@ pluralize@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/pluralize/-/pluralize-4.0.0.tgz#59b708c1c0190a2f692f1c7618c446b052fd1762"
 
-postcss@^6.0.1:
-  version "6.0.1"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-6.0.1.tgz#000dbd1f8eef217aa368b9a212c5fc40b2a8f3f2"
-  dependencies:
-    chalk "^1.1.3"
-    source-map "^0.5.6"
-    supports-color "^3.2.3"
-
 postcss@^6.0.2:
   version "6.0.2"
   resolved "https://registry.yarnpkg.com/postcss/-/postcss-6.0.2.tgz#5c4fea589f0ac3b00caa75b1cbc3a284195b7e5d"