Don't watch or compile .css files

This was a non-standared feature in LibSass we had to support. It
is being removed in LibSass 3.6.0.

This prevents people from output their source directory.

See sass/libsass#2611
See #2184
See #2006
See #1933
See #1925
See #1867
See #1845

Author: xzyfer

lib/watcher.js

@@ -9,7 +9,7 @@ watcher.reset = function(opts) {
   config = clonedeep(opts || config || {});
   var options = {
     loadPaths: config.includePath,
-    extensions: ['scss', 'sass', 'css'],
+    extensions: ['scss', 'sass'],
     follow: config.follow,
   };
 

package.json

@@ -67,7 +67,7 @@
     "node-gyp": "^3.3.1",
     "npmlog": "^4.0.0",
     "request": "2.87.0",
-    "sass-graph": "^2.2.4",
+    "sass-graph": "^3.0.0",
     "stdout-stream": "^1.4.0",
     "true-case-path": "^1.0.2"
   },