ENH: set display.max_seq_items default != None
API: Series.ravel compat with ndarray
Merge pull request #5759 from jreback/ravel

API: Series.ravel compat with ndarray
Merge pull request #5753 from y-p/PR_max_seq_items

ENH: set display.max_seq_items default != None
DOC: remove travis mentions in CONTRIBUTING.md. It just works now.
DOC: more CONTRIBUTING.md guidance
BUG: don't lose dtypes when concatenating empty array-likes
BUG: make _concat_compat respect dimensions when concatenating empty arrays
TST: fix tests, stop using deprecated numpy dtypes