refactor: get default ignoreRoot from ignore-by-default

Switches the default ignoreRoot to a list obtained from the ignore-by-default
package. See <https://github.com/novemberborn/ignore-by-default>.

This allows nodemon to tap into a shared list of directories it should ignore
when watching for changes. E.g. compared to the original list it's already been
extended with `.nyc_output` and `coverage` directories.

lib/config/defaults.js

@@ -1,3 +1,5 @@
+var ignoreRoot = require('ignore-by-default').directories()
+
 // default options for config.options
 module.exports = {
   restartable: 'rs',
@@ -9,7 +11,7 @@ module.exports = {
     // compatible with linux, mac and windows, or make the default.js
     // dynamically append the `.cmd` for node based utilities
   },
-  ignoreRoot: ['.git', 'node_modules', 'bower_components', '.sass-cache'],
+  ignoreRoot: ignoreRoot,
   watch: ['*.*'],
   stdin: true,
   runOnChangeOnly: false,

package.json

@@ -49,6 +49,7 @@
     "chokidar": "^1.2.0",
     "debug": "^2.2.0",
     "es6-promise": "^3.0.2",
+    "ignore-by-default": "^1.0.0",
     "lodash.defaults": "^3.1.2",
     "minimatch": "^3.0.0",
     "ps-tree": "^1.0.1",