Fix problems in package.json

- fix missing index.js (fixes vail-systems/node-mfcc#2)
- update version numbers
- add missing dependency

package.json

@@ -14,6 +14,7 @@
   },
   "main": "index.js",
   "files": [
+    "index.js",
     "mfcc.js",
     "src",
     "test",
@@ -32,8 +33,9 @@
   ],
   "dependencies": {
     "commander": "^2.8.1",
-    "dct": "^0.0.2",
-    "fft-js": "0.0.6",
+    "dct": "^0.0.3",
+    "fft-js": "0.0.9",
+    "signal-windows": "^0.0.1",
     "wav": "^1.0.0"
   }
 }