Add SeleniumBase custom exceptions

Author: mdmintz

seleniumbase/common/exceptions.py

@@ -0,0 +1,12 @@
+""" SeleniumBase Exceptions
+    NoSuchFileException => Used by self.assert_downloaded_file(...)
+    TimeLimitExceededException => Used by "--time-limit=SECONDS"
+"""
+
+
+class NoSuchFileException(Exception):
+    pass
+
+
+class TimeLimitExceededException(Exception):
+    pass