experDesign 0.2.0

• New follow_up() and follow_up2() to continue an experiment safely (#22).

• New check_data() to check the input data (#37).

• New compare_index() to compare different indexes per batch.

• Use all categories combined (column mix_cat) for comparing the batches.

• Increased the internal coherence of checks.

• Added thesis advisers on the description.

• Update documentation.