Use pkg_resources to get version

Current osprofiler can't show version due to
wrong way to generate module version.
Use pkg_resources to get version.

Note: we don't want to usr pbr in runtime.

Closes-Bug: #1551079
Change-Id: I5b728c9b8295620b806335e7d95f9a4fbc33d1cc

osprofiler/__init__.py

@@ -13,19 +13,11 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import os
-
-from six.moves import configparser
+import pkg_resources
 
 from osprofiler import _utils as utils
 
 
 utils.import_modules_from_package("osprofiler._notifiers")
 
-_conf = configparser.ConfigParser()
-_conf.read(os.path.join(
-    os.path.dirname(os.path.dirname(__file__)), "setup.cfg"))
-try:
-    __version__ = _conf.get("metadata", "version")
-except (configparser.NoOptionError, configparser.NoSectionError):
-    __version__ = None
+__version__ = pkg_resources.get_distribution("osprofiler").version

setup.py

@@ -1,7 +1,27 @@
-#!/usr/bin/env python
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
+# THIS FILE IS MANAGED BY THE GLOBAL REQUIREMENTS REPO - DO NOT EDIT
 import setuptools
 
+# 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
+try:
+    import multiprocessing  # noqa
+except ImportError:
+    pass
+
 setuptools.setup(
-    setup_requires=['pbr'],
+    setup_requires=['pbr>=1.8'],
     pbr=True)