[FIX] errorreporting: Remove use of pip internal api

[ales-erjavec]

Issue

Error reporting uses internal pip api, which will be moved in Pip 10.

Description of changes

Remove use of pip internal api

Includes

• Code changes
• Tests
• Documentation

[codecov-io]

Codecov Report

Merging #2724 into master will increase coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2724      +/-   ##
==========================================
+ Coverage   76.03%   76.03%   +<.01%     
==========================================
  Files         338      338              
  Lines       59628    59628              
==========================================
+ Hits        45339    45341       +2     
+ Misses      14289    14287       -2

[jerneju]

Traceback (most recent call last):
  File "/venv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 2459, in version
    return self._version
  File "/venv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 2545, in __getattr__
    raise AttributeError(attr)
AttributeError: _version

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/orange3/Orange/canvas/application/errorreporting.py", line 245, in handle_exception
    return ErrorReporting.handle_exception(exc)
  File "/usr/lib/python3.5/unittest/mock.py", line 1157, in patched
    return func(*args, **keywargs)
  File "/orange3/Orange/canvas/application/errorreporting.py", line 195, in handle_exception
    for dist in pkg_resources.working_set))
  File "/orange3/Orange/canvas/application/errorreporting.py", line 195, in <genexpr>
    for dist in pkg_resources.working_set))
  File "/venv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 2464, in version
    raise ValueError(tmpl % self.PKG_INFO, self)
ValueError: ("Missing 'Version:' header and/or PKG-INFO file", Orange [unknown version] (/orange3))
-------------------------------------------------------------------------------
Fatal Python error: Cannot recover from stack overflow.

[ales-erjavec]

Which version of setuptools do you have installed (pip list --format=freeze | grep setuptools)

How was orange3 installed and what does /orange3/Orange3.egg-info/PKG-INFO contain

[jerneju]

setuptools==36.5.0

PKG-INFO: Version: 3.8.0.dev0+cb8ab62

[ales-erjavec]

I was unable to duplicate the error, but the error is part of the documented Distribution.version behavior.

[jerneju]

Now it does not crash and a list of installed packages with their versions is sent to the server.