Log Message:
py-coverage: updated to 4.5

Version 4.5:

- A new kind of plugin is supported: configurators are invoked at start-up to
  allow more complex configuration than the .coveragerc file can easily do.
  See :ref:api_plugin for details.  This solves the complex configuration
  problem described in issue 563_.

- The fail_under option can now be a float.  Note that you must specify the
  [report] precision configuration option for the fractional part to be
  used.  Thanks to Lars Hupfeldt Nielsen for help with the implementation.
  Fixes issue 631_.

- The include and omit options can be specified for both the [run]
  and [report] phases of execution.  4.4.2 introduced some incorrect
  interactions between those phases, where the options for one were confused
  for the other.  This is now corrected, fixing issue 621_ and issue 622_.
  Thanks to Daniel Hahler for seeing more clearly than I could.

- The coverage combine command used to always overwrite the data file, even
  when no data had been read from apparently combinable files.  Now, an error
  is raised if we thought there were files to combine, but in fact none of them
  could be used.  Fixes issue 629_.

- The coverage combine command could get confused about path separators
  when combining data collected on Windows with data collected on Linux, as
  described in issue 618_.  This is now fixed: the result path always uses
  the path separator specified in the [paths] result.

- On Windows, the HTML report could fail when source trees are deeply nested,
  due to attempting to create HTML filenames longer than the 250-character
  maximum.  Now filenames will never get much larger than 200 characters,
  fixing issue 627_.  Thanks to Alex Sandro for helping with the fix.