Fixed Issue 85 by changing the broken link

Fixes qiskit-community#85 as before the tutorial link in the README.md was broken(showing 404) but now I have fixed it by a working link for that tutorial.

Cryptography/README.md

@@ -2,4 +2,4 @@
 ## QRandom --> Generates random numbers.
 The random number is directly generated from a Hadamard gate using Qiskit Terra. It is similar to rolling an `n`-faced dice, where `n` is the number of qubits. It is the worst way to generate random numbers using a quantum computer but the sequence developed is truly random. 
 
-For a more detailed example of generating random variates from various distributions using Qiskit aqua, take a look at [this tutorial](https://github.com/Qiskit/qiskit-tutorials/blob/master/qiskit/aqua/generating_random_variates.ipynb).
+For a more detailed example of generating random variates from various distributions using Qiskit aqua, take a look at [this tutorial](https://github.com/Qiskit/qiskit-tutorials/blob/master/legacy_tutorials/aqua/generating_random_variates.ipynb).