py2: fix FileNotFoundError does not exist [GH-5]

Thanks @3v1n0 for reporting the issue and proposing the fix.

Author: Sarcasm

compdb/includedb.py

@@ -11,6 +11,12 @@
 
 from compdb.models import CompilationDatabaseInterface
 
+try:
+    FileNotFoundError
+except NameError:
+    # py2
+    FileNotFoundError = IOError
+
 logger = logging.getLogger(__name__)