Pyexcel-xls

--------------------------------------------------------------------------------

**Removed**

. `46 <https://github.com/pyexcel/pyexcel-xls/issues/46>`_: remove the hard
pin on xlrd version < 2.0

**Added**

. `47 <https://github.com/pyexcel/pyexcel-xls/issues/47>`_: limit support to
persist datetime.timedelta. see more details in doc

--------------------------------------------------------------------------------

**Updated**

. lock down xlrd version less than version 2.0, because 2.0+ does not support
xlsx read

--------------------------------------------------------------------------------

**Updated**

. Restrict this library to get installed on python 3.6+, because pyexcel-io
0.6.0+ supports only python 3.6+.

--------------------------------------------------------------------------------

**Updated**

. New style xlsx plugins, promoted by pyexcel-io v0.6.2.

--------------------------------------------------------------------------------

**Added**

. `35 <https://github.com/pyexcel/pyexcel-xls/issues/35>`_, include tests

--------------------------------------------------------------------------------

**Updated**

. `34 <https://github.com/pyexcel/pyexcel-xlsx/issues/34>`_: pin
openpyxl>=2.6.1