Ignore node_modules during login

lib/output/base.js

@@ -49,11 +49,13 @@ Output.prototype.generate = function() {
 
     // Initialize the generation
     .then(function() {
+        that.log.debug.ln('preparing the generation');
         return that.prepare();
     })
 
     // Process all files
     .then(function() {
+        that.log.debug.ln('listing files');
         return that.book.fs.listAllFiles(that.book.root);
     })
 
@@ -89,6 +91,7 @@ Output.prototype.generate = function() {
 
     // Finish the generation
     .then(function() {
+        that.log.debug.ln('finishing the generation');
         return that.finish();
     })
 
@@ -103,6 +106,7 @@ Output.prototype.prepare = function() {
         '.gitignore',
         '.ignore',
         '.bookignore',
+        'node_modules',
 
         // The configuration file should not be copied in the output
         this.book.config.path,