work on anon-fn checking and pfn
fn> is now broken, deprecated anyway.

core/fn and fn ranges act the same now.
Better propagation of expected types for unannotated fn's
remove tests for for>, fn>, let>, doseq>, dotimes>
add isa/multimethod tests
start removing fn>
3 tests fail
add travis.yml
pfn actually returns a poly type
use check-below in more places
more tests
standardise :path in TypeFilter
don't simplify filter sets based on -bot
don't check filters twice in check-fn-method1
check below for var and set!
more check-below cases
fix doseq macroexpansion
fix doseq macroexpansion
case for NoFilter in subst-filter
fix test