TST: skip some tests if scikits is installed but not scipy GH3376
DOC: correct release notes version
Merge pull request #4349 from cpcloud/add-urlerror-info

DOC: correct release notes version
Merge pull request #4320 from y-p/GH3376

TST: skip some tests if scikits is installed but not scipy GH3376
BLD: Use git describe to generate the version string for dev versions
BLD: Strip leading v in git describe version string
DOC/BUG: fix doc build error because a frame was being redefined
BLD: remove ISRELEASED flag
Merge pull request #4218 from y-p/PR_dev_version_string

BLD: Use 'git describe' to generate the version string for dev versions
Merge pull request #4350 from cpcloud/fixup-indexing-doc-failures

DOC/BUG: fix doc build error because a frame was being redefined
ENH: add integer sheetname support
DOC: add documentation for reading from the index of a sheet