Longbow v1.5.0

The changes in this release are summarised below:

1. Change of license from GPLv2 to the BSD 3 clause license. This will resolve
   the copy-left issues a number of projects are having (Issue #30).

2. Fix for problem where environment is not properly loaded on some machines,
   this is a non-login shell related problem (Issue #4).

3. Removal of capitalisation from around the whole project for convenience
   (Issues #26 #28 #46 #47).

4. Longbow will now clean out recovery files upon successful completion of the
   session (Issue #24).

5. Bash autocomplete creation added to the setup.py (Issue #23 #49).

6. Fix for bad exit from recovery mode when user issues a keyboard interrupt
   (ctrl-c) (Issue #25).

7. Fix for monitoring phase causing CPU to be spun up to 100% (Issue #35).

8. Fix for bug when examples are downloaded in app, the original zip archive
   is not removed after extraction (Issue #34).

9. Fixed a bug in setup script with the python version check code (Issue #32).

10. Python 3.6 added to supported versions (Issue #33).

11. All public methods in the Longbow API can now be accessed from a single
    import, (ie "import longbow" then "longbow.somemethod()") (Issue #27).