Create gui test

[joakim-hove]

Task
Add a small script build/bin/gui_test which should be a one-command-no-setup to invoke the gui on a test case.

Approach
The idea is that with this script in place you can run:

cmd> cd build
cmd> make
cmd> bin/gui_test

in the ert repository. The gui_test script will set some environment variables and then invoke the ert gui properly. Some status information is printed in the console - it is important to read and understand this.

By default the script will invoke ert with this [config file[(https://github.com/Statoil/ert/blob/master/test-data/local/snake_oil_no_data/snake_oil.ert). The actual test will be perfomed in a temporary directory, by default the temporary directory will be deleted afterwards, but if you pass option: --keep the folder will be retained e.g. for debugging.

Optionally you can pass an alternative config file as commandline argument:

bin/gui_test /path/to/my_config_file

in that case the simulation will be performed in-place and no cleanup will be done afterwards.

Pre un-WIP checklist

• Statoil tests pass locally
• Have completed graphical integration test steps

[stefoss23]

Works fine.