Refactor exit_code implementation

cmd2.Cmd.cmdloop() now returns self.exit_code which should be an integer

Also:
- Refactored examples to call sys.exit(app.cmdloop()) in their __main__
- Running transcript tests now sets the exit_code accordingly based on success/failure
- Updated CHANGELOG
- Updated README
- Updated Sphinx docs
- Added unit test for case when transcript test fails

1 files changed, 3 insertions, 3 deletions

diff --git a/examples/example.py b/examples/example.py
index 9f9c0304..a1ec893c 100755
--- a/examples/example.py
+++ b/examples/example.py
@@ -10,9 +10,8 @@ Running `python example.py -t transcript_regex.txt` will run all the commands in
 the transcript against example.py, verifying that the output produced matches
 the transcript.
 """
-
-import random
 import argparse
+import random
 
 import cmd2
 
@@ -82,5 +81,6 @@ class CmdLineApp(cmd2.Cmd):
 
 
 if __name__ == '__main__':
+    import sys
     c = CmdLineApp()
-    c.cmdloop()
+    sys.exit(c.cmdloop())