Avoid new versions of the xlrd package.

xlrd reads Excel files, but its ability to read .xlsx files was
recently removed and it's no longer actively maintained. FlowCal
still requires xlrd to read .xlsx files with old versions of
pandas where the alternative (and now recommended) openpyxl engine
is not recognized. This fix avoids the new versions of xlrd to
ensure it can still read .xlsx files. (FlowCal still uses openpyxl
first where available.)

doc/getting_started/install_python.rst

@@ -17,7 +17,7 @@ Alternatively, download ``FlowCal`` from `here <https://github.com/taborlab/Flow
 * ``scikit-image`` (>=0.10.0)
 * ``scikit-learn`` (>=0.16.0)
 * ``pandas`` (>=0.23.0)
-* ``xlrd`` (>=0.9.2)
+* ``xlrd`` (>=0.9.2,<2.0.0)
 * ``openpyxl`` (>=2.2.0)
 
 If you have ``pip``, a ``requirements.txt`` file is provided, such that the required packages can be installed by running::

requirements.txt

@@ -6,5 +6,5 @@ matplotlib>=2.0.0
 scikit-image>=0.10.0
 scikit-learn>=0.16.0
 pandas>=0.23.0
-xlrd>=0.9.2
+xlrd>=0.9.2,<2.0.0
 openpyxl>=2.2.0

setup.py

@@ -94,7 +94,7 @@ def find_version(file_path):
                       'scikit-image>=0.10.0',
                       'scikit-learn>=0.16.0',
                       'pandas>=0.23.0',
-                      'xlrd>=0.9.2',
+                      'xlrd>=0.9.2,<2.0.0',
                       'openpyxl>=2.2.0'],
 
     # List additional groups of dependencies here (e.g. development