bump VERSION

Version 1.7.1

Updated changlog

Version 1.6.1

Alternative now lazily loads counts, so there's no database access

penalty when returning a list of alternatives.

Version 1.5.3.

Version 1.5.2.

Version bump.

1.5.0: woot!

Version bump to 1.5.0.

Added contributors to credit page.
Added contributing section to README.