travis: extraction of dev config into script

• Extracts developer configuration into a script file so it can be reused by other components (e.g. Docker).

• Adds some bold warnings before and after the script execution that this config should NOT be used in production mode.

• Changes the initial configuration procedure from single inveniomananage calls to a single file append. Proper types are assigned as they would appear when using the inveniomanage.

Signed-off-by: Marco Neumann <marco@crepererum.net>