Fix python namespaces for test runs

We need to make sure we don't use namespaced versions that are already installed
on the system but rather use local version from current sources

test/testall.py

@@ -24,6 +24,13 @@ pkgpath = os.path.dirname(__file__) or '.'
 sys.path.append(pkgpath)
 os.chdir(pkgpath)
 
+# Make sure we use local version of beetsplug and not system namespaced version
+# for tests
+try:
+    del sys.modules["beetsplug"]
+except KeyError:
+    pass
+
 def suite():
     s = unittest.TestSuite()
     # Get the suite() of every module in this directory beginning with