minor docstring cleanup in crystals.py and tensor_product.py

[dwbump]

This removes a test in tensor_product.py that is a repetition of a previous test (at line 193).
It also removes an obsolete comment in crystals.py.

CC: @sagetrac-sage-combinat

Component: combinatorics

Issue created by migration from https://trac.sagemath.org/ticket/3032

[mwhansen]

comment:1

Attachment: 9607.patch.gz

[sagetrac-mabshoff]

comment:2

Merged in Sage 3.0.1.alpha1