Merge branch 'release/0.2.6' into develop
lein-release plugin: bumped version from 0.2.6 to 0.2.7-SNAPSHOT for next development cycle
bump version on getting started page
bump cljs in docs site
test all util functions
types testing
do not force all refs to nil

this merges in an unconventional manner (from right to left) since
user supplied attrs are fed first to merge-props.
Merge pull request #20 from pyr/develop

do not force all refs to nil
Merge pull request #19 from racehub/feature/types_testing

tests for the types namespace
bump changelog
lein-release plugin: preparing 0.2.7 release
Merge branch 'release/0.2.7'