actually add own package to pkg_resources.working_set

this allows to actually use entry-points if available

fixes #295

Author: RonnyPfannschmidt

setup.py

@@ -20,8 +20,10 @@ def scm_config():
     src = os.path.join(here, "src")
     egg_info = os.path.join(src, "setuptools_scm.egg-info")
     has_entrypoints = os.path.isdir(egg_info)
+    import pkg_resources
 
     sys.path.insert(0, src)
+    pkg_resources.working_set.add_entry(src)
     from setuptools_scm.hacks import parse_pkginfo
     from setuptools_scm.git import parse as parse_git
     from setuptools_scm.version import guess_next_dev_version, get_local_node_and_date