Change url variable to the updated UVES data

* Switching to data.astropy.org

Author: migueldvb

tutorials/UVES/UVES.ipynb

@@ -93,7 +93,7 @@
      "input": [
       "import tarfile\n",
       "from astropy.utils.data import download_file\n",
-      "url = 'http://python4astronomers.github.io/_downloads/astropy_UVES.tar.gz'\n",
+      "url = 'http://data.astropy.org/tutorials/UVES/data_UVES.tar.gz'\n",
       "f = tarfile.open(download_file(url, cache=True), mode='r|*')\n",
       "location_for_data_file = '.'  # CHANGE TO WHEREVER YOU WANT THE DATA TO BE EXTRACTED\n",
       "f.extractall(path=location_for_data_file)"