CLN: remove unused travis network build cache, simplify ci/
DOC: fix to_json docstring nesting issue
Merge pull request #3930 from cpcloud/json-docstring-fix

DOC: fix to_json docstring nesting issue
Merge pull request #3929 from y-p/PR_PTF_no_more

PTF no more
CLN: Add .gitattributes to fix crlf issues.

Make pickle binary (to handle some issues where git was mishandling
pickled files)
CLN: CRLF --> LF