Corrupted CNNDM model file

Hello,

It seems the CNNDM model file available for download is corrupted. Executing the following command:
```
tar -zxvf model.tar.gz 
```
Results in the following error message:
```
gzip: stdin: unexpected end of file
tar: Unexpected EOF in archive
tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now
```

