Readme update

README.md

@@ -18,7 +18,12 @@ This repo contains a demo of:
  - A c++ program that will simulate a crash
  - The `gdb` incantation to make the crash backtrace visible in the travis logs
 
-See the `.travis.yml` for detailed instructions and the resulting logs at <https://travis-ci.org/springmeyer/travis-coredump/>. One of the travis runs should crash with a nice backtrace showing your the file and line number of the bug:
+See `.travis.yml` for detailed instructions you can copy into your own `.travis.yml`. See sample logs at <https://travis-ci.org/springmeyer/travis-coredump/>. This repo is configured so that with two runs in the travis matix:
+
+  - One run tests a program that does not crash and therefore the build should cleanly pass
+  - The other run tests a program that does crash, reports the backtrace, then exits the run with the same errorcode as generated by the crash.
+
+The backtrace should reveal to you the file and line number of the bug:
 
 ```
 Core was generated by `./test'.