skbio.maths -> skbio.math
Merge pull request #1537 from ElBrogrammer/brah-i-learned-maths

skbio.maths -> skbio.math
updates to remove cogent dependency
removed cogent dependency
removed one of the cogent dependencies
updated for skbio interface change
fixed some errors due to bad imports
Minor doc fixes for issue #1533
Merge pull request #1539 from gregcaporaso/issues-1502-1538

work on removing cogent dependency and handling an skbio interface change
Merge pull request #1540 from wdwvt1/group_sig_docs

Minor doc fixes for issue #1533
Use skbio's alpha diversity metrics
Remove qiime.pycogent_backports.alpha_diversity

You can dance if you want to
Add links to scikit-bio alpha diversity docs

Thanks for suggesting this @ElDeveloper!
replace more observed_species refs to observed_otus
Resolves issue #1398

This issue is incorrectly titled - the G-test error occurs here. In short, this PR removes the abilit to use group_significance.py on a table which is relative abundance.
Resolves forum users concern

Forum posts frequently cite the warning that table has no metadata as an error when using group_significance.py. It actually does not cause failures, just a warning. This clarifies the message.
Missing word.
Fixes #1546
Fixes #1547.
Merge pull request #1542 from ElBrogrammer/brah-i-alpha-diversity

Remove PyCogent alpha diversity dependency