Updating mnist filenames to match downloaded conventions

This will prevent library users from having to figure out the filename conventions used here, as the updated files in this pull request match those downloaded from the mnist website after unzipping them.

main.js

@@ -78,8 +78,8 @@
  function mnist() {
  log('parsing MNIST data ...');
 
- var data = fs.readFileSync('./mnist/train-images.idx3-ubyte'),
- labels = fs.readFileSync('./mnist/train-labels.idx1-ubyte'),
+ var data = fs.readFileSync('./mnist/train-images-idx3-ubyte'),
+ labels = fs.readFileSync('./mnist/train-labels-idx1-ubyte'),
  training = [],
  testing = [],
  pixels = [],
@@ -110,8 +110,8 @@
  pixels = [];
  }
 
- data = fs.readFileSync('./mnist/t10k-images-2.idx3-ubyte');
- labels = fs.readFileSync('./mnist/t10k-labels.idx1-ubyte');
+ data = fs.readFileSync('./mnist/t10k-images-idx3-ubyte');
+ labels = fs.readFileSync('./mnist/t10k-labels-idx1-ubyte');
 
  for(image = 0; image < config.testing_set; image++) {
  for(y = 4; y < config.image_size + 4; y++)
@@ -197,4 +197,4 @@
  }
  };
  }
-})(console.log);
+})(console.log);