Merge pull request #112 from bendmorris/master

Add citation command to get citation info for the retriever itself or for individual datasets.
Use already downloaded raw data for regression testing

This moves the data files for all but one dataset into the test
directory to save time on downloading and avoid issue with Travis
sometimes failing to download files.

nosetests needs to be run from inside the test directory.

Required addition of a setup fixture for the module to download
the scripts.
Change Travis YAML to run nosetests from test directory
Merge pull request #113 from ethanwhite/tests-local-files

Use already downloaded raw data for regression testing
Allow testing to be run from the root directory using nosetests
Add some basic unit tests for functions with no dependencies
Add tests of automated identification of the delimiter
Moving simple engine creation to a fixture

This is probably not the right way to do this, but it's all I can
get to work at the moment.
Clarify and expand auto_get_columns() docstring
Add tests for auto_get_columns

1. Simple test for identifying column names
2. Test of the cleanup functions to remove special characters and
   database keywords
Accommodate change in maximum length of a field in the BBS data
Adding tests for extracting values from lines of data
Changes the character length of english common name, spanish common name, species from 30 to 50.
Merge pull request #120 from embaldridge/master

Fix for Issue 116, BBS database won't import with postgres.
Merge pull request #115 from ethanwhite/docstring-fix

Clarify and expand auto_get_columns() docstring
Merge pull request #114 from ethanwhite/simple-tests

Add simple unit tests
Data source should be explicitly passed into add_to_table function, not saved as a class member.
Moving split_on_delimiter and auto_get_columns to Table.