Update dependencies

Author: ai

.travis.yml

@@ -5,3 +5,5 @@ node_js:
   - "8"
   - "6"
   - "4"
+install:
+  - YARN_IGNORE_ENGINES=true yarn

package.json

@@ -14,29 +14,29 @@
   "license": "MIT",
   "repository": "postcss/postcss-scss",
   "dependencies": {
-    "postcss": "^6.0.3"
+    "postcss": "^6.0.15"
   },
   "devDependencies": {
-    "babel-core": "^6.25.0",
-    "babel-eslint": "^7.2.3",
+    "babel-core": "^6.26.0",
+    "babel-eslint": "^8.1.2",
     "babel-plugin-add-module-exports": "0.2.1",
-    "babel-plugin-precompile-charcodes": "1.0.0",
-    "babel-preset-env": "^1.5.2",
+    "babel-plugin-precompile-charcodes": "1.1.0",
+    "babel-preset-env": "^1.6.1",
     "del": "^3.0.0",
-    "eslint": "^4.0.0",
+    "eslint": "^4.14.0",
     "eslint-config-postcss": "2.0.2",
     "gulp": "3.9.1",
-    "gulp-babel": "6.1.2",
-    "gulp-changed": "^3.1.0",
+    "gulp-babel": "7.0.0",
+    "gulp-changed": "^3.2.0",
     "gulp-eslint": "^4.0.0",
-    "gulp-jest": "^2.0.0",
+    "gulp-jest": "^3.0.1",
     "gulp-json-editor": "2.2.1",
-    "gulp-sourcemaps": "^2.6.0",
-    "jest": "^20.0.4",
-    "lint-staged": "^4.0.0",
-    "postcss-parser-tests": "^6.0.1",
+    "gulp-sourcemaps": "^2.6.3",
+    "jest": "^22.0.4",
+    "lint-staged": "^6.0.0",
+    "postcss-parser-tests": "^6.1.0",
     "pre-commit": "^1.2.2",
-    "run-sequence": "1.2.2"
+    "run-sequence": "2.2.1"
   },
   "scripts": {
     "lint-staged": "lint-staged",
@@ -59,6 +59,12 @@
       "jest": true
     }
   },
+  "jest": {
+    "testEnvironment": "node",
+    "modulePathIgnorePatterns": [
+      "<rootDir>/build"
+    ]
+  },
   "babel": {
     "presets": [
       [