added exception test for bad schema
added exception test for bad schema

walshb/pyavroc,crs4/pyavroc,crs4/pyavroc,Byhiras/pyavroc,walshb/pyavroc,Byhiras/pyavroc,crs4/pyavroc,Byhiras/pyavroc,Byhiras/pyavroc,walshb/pyavroc,walshb/pyavroc