BUG: mnist load data reshape error

[rcabanasdepaz]

The following code

import inferpy.datasets.mnist as mnist
mnist.load_data(num_instances=1000, digits=[0])

raises the error:

ValueError: cannot reshape array of size 768320 into shape (1000,784)

[rcabanasdepaz]

This has been solved by adding a different input parameter num_instances_test for specifying the number of test instances.