Version bump govspeak to 1.6.1

1.6.1 fixes parsing errors for $LegislativeList and $PriorityList when
they don't follow an empty newline.

Fixes
https://trello.com/c/hel31WzU/159-bug-html-for-legislative-list-appears-on-page
Merge pull request #130 from alphagov/bump-govspeak-to-1.6.1

Version bump govspeak to 1.6.1