Add pyav hooks (#29)

Add pyav hook

pyav uses a Cython module which imports sub-modules. These are not
normally detected by PyInstaller. This hook uses collect_submodules
to add the missing modules as hidden imports.

Includes a new test for av(pyav)

news/29.new.rst

@@ -0,0 +1 @@
+Add a hook for ``pyav(av)`` which has hidden imports.

requirements-test.txt

@@ -31,6 +31,7 @@ pyzmq==19.0.0
 Unidecode==1.1.1
 zeep==3.4.0
 sentry-sdk==0.15.1
+av==8.0.2
 
 # ------------------- Python Version/Platform (OS) specifics
 # These libraries only support python above 3.5

src/_pyinstaller_hooks_contrib/hooks/stdhooks/hook-av.py

@@ -0,0 +1,14 @@
+# ------------------------------------------------------------------
+# Copyright (c) 2020 PyInstaller Development Team.
+#
+# This file is distributed under the terms of the GNU General Public
+# License (version 2.0 or later).
+#
+# The full license is available in LICENSE.GPL.txt, distributed with
+# this software.
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+# ------------------------------------------------------------------
+from PyInstaller.utils.hooks import collect_submodules
+
+hiddenimports = ['fractions'] + collect_submodules("av")

src/_pyinstaller_hooks_contrib/tests/test_libraries.py

@@ -303,3 +303,10 @@ def test_iminuit(pyi_builder):
     pyi_builder.test_source("""
         from iminuit import Minuit
         """)
+
+
+@importorskip('av')
+def test_av(pyi_builder):
+    pyi_builder.test_source("""
+        import av
+        """)