Need random byte support

[lij55]

First of all, thanks for the great tool for generating mock data so easily.
It can generate random data for a lot of different data type.

However, for binary format data, it create random string instead of real binary data.
It would be better to generate real binary format data for 'bytea' format of postgresql.

[lij55]

#3

[faisaltheparttimecoder]

Thanks @lij55 for the pull request, the pull looks good and its now merged. closing this one