[Checkins] [zopefoundation/BTrees] ece3ff: Remove vestigial test_suite methods.

[Jason Madden]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/BTrees
  Commit: ece3ff2176cdf9dee64c00e93619df249d76514a
      https://github.com/zopefoundation/BTrees/commit/ece3ff2176cdf9dee64c00e93619df249d76514a
  Author: Jason Madden <jamadden at gmail.com>
  Date:   2020-03-05 (Thu, 05 Mar 2020)

  Changed paths:
    M .travis.yml
    M BTrees/_base.py
    M BTrees/tests/common.py
    M BTrees/tests/testBTrees.py
    M BTrees/tests/testBTreesUnicode.py
    M BTrees/tests/testConflict.py
    M BTrees/tests/test_IFBTree.py
    M BTrees/tests/test_IIBTree.py
    M BTrees/tests/test_IOBTree.py
    M BTrees/tests/test_LFBTree.py
    M BTrees/tests/test_LLBTree.py
    M BTrees/tests/test_LOBTree.py
    M BTrees/tests/test_Length.py
    M BTrees/tests/test_OIBTree.py
    M BTrees/tests/test_OLBTree.py
    M BTrees/tests/test_OOBTree.py
    M BTrees/tests/test__base.py
    M BTrees/tests/test_btreesubclass.py
    M BTrees/tests/test_check.py
    M BTrees/tests/test_fsBTree.py
    M BTrees/tests/test_utils.py

  Log Message:
  -----------
  Remove vestigial test_suite methods.

And other small tweaks to bring test coverage up. Turns out there were several test methods being needlessly skipped.