added __init__.py to examples and tests subdirectories

pysstv/examples/__init__.py

@@ -0,0 +1,3 @@
+#!/usr/bin/env python
+
+__all__ = ['overlay', 'pyaudio_sstv', 'repeater']

pysstv/tests/__init__.py

@@ -0,0 +1,3 @@
+#!/usr/bin/env python
+
+__all__ = ['common', 'test_color', 'test_sstv']