remove licence file, add more description

DESCRIPTION

@@ -3,10 +3,10 @@ Title: Recurrent Neural Network
 Version: 0.9.8
 Authors@R: c(person("Bastiaan", "Quast", email = "bquast@gmail.com", role = c("aut", "cre")),
              person("Dimitri", "Fichou", email = "dimitrifichou@gmail.com", role = "aut"))
-Description: Implementation of a Recurrent Neural Network in R.
+Description: Implementation of a Recurrent Neural Network architectures in native R, including Long Short-Term Memory (LSTM), Gated Recurrent Unit (GRU) and vanilla RNN.
 Depends: 
     R (>= 3.2.2)
-License: GPL-3 + file LICENSE
+License: GPL-3
 LazyData: true
 RoxygenNote: 6.1.1
 URL: http://qua.st/rnn, https://github.com/bquast/rnn