Switch to pbr

Resolves issue #16
Merge pull request #28 from jd/jd/pbr

Switch to pbr
remove version from setup.cfg and rely on git tag

Change-Id: Ib30d0538f4d17a8890a0001a4d0116b08dd74868
update history and announce file for release

Change-Id: I830d1755c9ed8dbf356edaf68243a01b1d6eb6ac
fix version number in blog announcement file

Change-Id: Ieac1a09728f2a62d5c5c372b78bf6ad480688eb9
Fix pip call in tox config

Tox passes --pre to pip, which means we get pre-release
versions of stuff. That breaks the docs build, but is
just a bad idea anyway, so override the setting so we
don't do it.

Change-Id: Iec89b12a969f34486005e8dc41cb189438b38959
add pypy to default test env list

Change-Id: I1fba36e54850c18fdb2720377566ad43ee5b8661
add pypy to travis config

Change-Id: Ib4b9b5a91b7cfce8241b7ad641bb0b959344dc2a
a work-around to avoid cpython bug (15881)

In python < 2.7.4, a lazy loading of package `pbr` will break setuptools if some other modules registered functions in `atexit`.
solution from: http://bugs.python.org/issue15881#msg170215
DOC: Updated index.rst: distribute -> setuptools

http://pythonhosted.org/setuptools/merge.html
Merge pull request #31 from westurner/patch-1

DOC: Updated index.rst: distribute -> setuptools
Merge pull request #30 from philiptzou/patch-1

a work-around to avoid cpython bug with atexit (15881)
use item access instead of temporary dict when ordering extensions
add test instance factory for the base, named, and hook managers

The class method make_test_instance constructs manager instances using a
predefined list of extensions, rather than loading from entry points.
make Extension responsible for formatting its target name
enabled extension manager test instance factory
driver extension manager test instance factory
simplify test instance factory contract

After some discussion, the make_test_instance factories expect a final
list of extensions, which simplifies creation and keeps responsibilities
better focused.  Users who wish to test their check functions should do
so separately.
Merge pull request #29 from drocco-007/master

Test instance factories
clean up docs for DriverManager

Change-Id: I71d96a5feb308efe3803899b1ee7954444dd7761