Dependencies (postcss#21)

* Update dependencies

* Update config of travis-ci

.travis.yml

@@ -1,11 +1,15 @@
+dist: trusty
 sudo: false
 language: node_js
+
 node_js:
   - stable
   - 6
   - 4
+
 before_install:
-  - npm i npm@latest -g
+  - npm i check-node-version -g
+  - check-node-version --node '>= 9' || npm i npm@latest -g
 
-after_success:
+after_script:
   - npm run coveralls

package.json

@@ -45,7 +45,7 @@
   "dependencies": {
     "bufferstreams": "^1.1.1",
     "gulp-util": "^3.0.8",
-    "postcss-html": "^0.8.0",
+    "postcss-html": "^0.11.0",
     "postcss-load-config": "^1.2.0",
     "postcss-load-options": "^1.2.0",
     "postcss-load-plugins": "^2.3.0",
@@ -55,16 +55,16 @@
     "postcss": ">=6.0.0"
   },
   "devDependencies": {
-    "coveralls": "^2.13.1",
-    "eslint": "^4.2.0",
+    "coveralls": "^3.0.0",
+    "eslint": "^4.11.0",
     "from2-array": "0.0.4",
     "gulp-rename": "^1.2.2",
-    "gulp-sourcemaps": "^2.6.0",
-    "mocha": "^3.4.2",
-    "nyc": "^11.0.3",
-    "postcss": "^6.0.6",
-    "postcss-less": "^1.1.0",
+    "gulp-sourcemaps": "^2.6.1",
+    "mocha": "^4.0.1",
+    "nyc": "^11.3.0",
+    "postcss": "^6.0.14",
+    "postcss-less": "^1.1.3",
     "proxyquire": "^1.8.0",
-    "sinon": "^2.3.7"
+    "sinon": "^4.1.2"
   }
 }