Require cppTango>=9.4.1 to import the library
The functionality for empty spectrum/image attributes, !493 (merged), requires fixes in cppTango 9.4.1. Ensure that PyTango is not used with an earlier version of cppTango.
Fixed a few typos, and other places where we mention cppTango 9.4.0.
Still to do in future MR: update AppVeyor and Gitlab CI to use the final 9.4.1 release.
Example of a failure:
In [2]: import tango
---------------------------------------------------------------------------
Exception Traceback (most recent call last)
<ipython-input-2-8f07f9801e42> in <module>
----> 1 import tango
/usr/local/lib/python3.7/dist-packages/tango/__init__.py in <module>
181 from .pytango_init import init as __init
182 __init()
--> 183 requires_tango("9.4.1", software_name="PyTango")
184
/usr/local/lib/python3.7/dist-packages/tango/utils.py in requires_tango(min_version, conflicts, software_name)
329 """
330 return __requires("Tango", min_version=min_version,
--> 331 conflicts=conflicts, software_name=software_name)
332
333
/usr/local/lib/python3.7/dist-packages/tango/utils.py in __requires(package_name, min_version, conflicts, software_name)
253 msg = "{0} requires {1} {2} but {3} installed".format(
254 software_name, package_name, min_version, curr_version)
--> 255 raise Exception(msg)
256
257 conflicts = map(LooseVersion, conflicts)
Exception: PyTango requires Tango 9.4.1 but 9.3.5 installed