v3.4.1

#1345, add --generate-config to generate a complete config
#1345, add --generate-summary-json
#1377, make anyM/allM on [] produce pure, rather than return
#1377, add a pure rule for every return variant
#1380, add counts as comments for --default
#1372, remove unnecessary brackets when suggesting forM_
#1372, suggest void (forM x y) to forM_ without the void
#1394, replace maximum [a, b] ==> max a b (and for min)
#1393, for QuickCheck, join . elements ==> oneOf
#1387, bypass camelCase hint for new tasty_... custom test prefix