dev(build): use more reliable setup code to read the current version

setup.py

@@ -104,8 +104,12 b' test_requirements = _get_requirements('
 
 
 def get_version():
-    version = pkgutil.get_data('rhodecode', 'VERSION')
-    return version.decode().strip()
+    here = os.path.abspath(os.path.dirname(__file__))
+    ver_file = os.path.join(here, "rhodecode", "VERSION")
+    with open(ver_file, "rt") as f:
+        version = f.read().strip()
+
+    return version
 
 
 # additional files that goes into package itself