pysal/spaghetti: v1.3 Stable Release

Changes Version 1.3 (2019-05-21) We closed a total of 12 issues (enhancements and bug fixes) through 5 pull requests, since our last release on 2019-05-14. Issues Closed add requirements_dev.txt to MANIFEST.in (#277) Update changelog (#279) version bump to include req_dev in MANIFEST.in (#278) v1.2 --> 1.3rc1 (for release candidate) (#276) Updating notebooks prior to v1.3 release (#275) updating README (#274) update notebooks following prior to v1.3 release (#158) Pull Requests Update changelog (#279) version bump to include req_dev in MANIFEST.in (#278) v1.2 --> 1.3rc1 (for release candidate) (#276) Updating notebooks prior to v1.3 release (#275) updating README (#274) The following individuals contributed to this release: James Gaboard