Bump devDependencies.

The Travis CI change is needed due to grunt-html's requirement of java 8.

.travis.yml

@@ -1,6 +1,8 @@
-language: node_js
+sudo: required
 
-sudo: false
+dist: trusty
+
+language: node_js
 
 git:
   depth: 10

package.json

@@ -29,19 +29,19 @@
     "grunt": "~0.4.5",
     "grunt-autoprefixer": "~3.0.0",
     "grunt-banner": "~0.6.0",
-    "grunt-contrib-clean": "~0.7.0",
-    "grunt-contrib-compress": "~0.14.0",
+    "grunt-contrib-clean": "~1.0.0",
+    "grunt-contrib-compress": "~1.0.0",
     "grunt-contrib-concat": "~0.5.1",
     "grunt-contrib-connect": "~0.11.2",
     "grunt-contrib-copy": "~0.8.0",
     "grunt-contrib-csslint": "~0.5.0",
     "grunt-contrib-cssmin": "~0.14.0",
     "grunt-contrib-htmlmin": "~0.6.0",
-    "grunt-contrib-jshint": "~0.12.0",
+    "grunt-contrib-jshint": "~1.0.0",
     "grunt-contrib-uglify": "~0.11.0",
     "grunt-contrib-watch": "~0.6.1",
     "grunt-csscomb": "~3.1.0",
-    "grunt-html": "~5.0.0",
+    "grunt-html": "~6.0.0",
     "grunt-contrib-jasmine": "~0.9.2",
     "grunt-jekyll": "~0.4.2",
     "grunt-jscs": "~2.7.0",