Add authoship info and remove stdout from test_predict_traits.py

Addresses #10 and #14
Add authorship to test_format_tree_and_trait_table.py

Addresses #12
Add authorship and remove call to unneeded functions in test_format.py

Addresses #4 and #11

Note: test_format.py still doesn't actually test anything.
Fix script that is called in test_metagenome_contributions.py

Addresses #7
Add GNU GPL V3 LICENSE file
Fix __copyright__ line in all scripts

Updated to "Copyright 2011-2013, The PICRUSt project"
Merge pull request #18 from mlangill/fix_tests

Fixes many of the minor issues with test scripts