Log Message:
(devel/R-purrr) Updated 0.3.3 to 0.3.4. TEST_DEPENDS added and now passes

# purrr 0.3.4

* Added documentation for exporting functions created with purrr
  adverb (@njtierney, #668). See `?faq-adverbs-export`.

* Added `none()`, which tests that a predicate is false for all elements
  (the opposite of `every()`) (@AliciaSchep, #735).