Correct display of tensorflow loading bars

[AlexandreSajus]

Only the last Tensorflow loading bar is showed when model.fit is called which means that the epoch number and the previous epochs are not shown

[AlexandreSajus]

I have no idea how to fix this currently, either we show the last output of the kernel and we don't get the previous epochs informations; or we show every output and we get the same loading bar multiple times

[MathisFederico]

Resolved by #38

[AlexandreSajus]

There might be a way to solve this by accumulating or replacing output according to special symbols sent by the tensorflow logger such as /r carriage return or /n newline

[MathisFederico]

Closed by #79