Heat: package improvement

[Thomas Goirand]

This is a general review of the package

debian/control
--------------
- Missing build-depends on dh-python, python-sphinx, python-setuptools (they are needed by the clean target, therefore shouldn't be in build-depends-indep)
- Missing build-depends-indep: python-alembic -> alembic python-oslo.versionedobjects, subunit
- Useless build-depends: python-extras, python-lockfile, python-lxml, python-paste, python-testrepository,
- Advice: remove python-qpid, since nobody uses it and unit tests are skipped if not present
- Missing depends: python-babel
- Useless depends: python-coverage, python-extras, python-hacking, python-lockfile,
  python-qpid (same as above), python-setuptools, python-sphinx

debian/rules
------------
- Wrong useage of && instead of ;
- rm -rf pbr*.egg <--- That's old cruft that should we get rid of
- no generation of the docs

debian/changelog
----------------
- It's comming from my package, but my debian/changelog has been scrapped

debian/*.postrm
---------------
- Incorrectly purges log files (wrong filenames). Note: this was also present in the Debian package, which I have just fixed.

[Daniil Trishkin (dtrishkin)]

Commits that related to improvement:
https://review.fuel-infra.org/#/c/12128/
https://review.fuel-infra.org/#/c/12661/