Add BASH script to run test against a local directory.

[Potherca]

This merge-request adds a script (based on runTests-dev.sh) that mounts a given local directory in the server-under-test.

This way it is trivial to run the test against a local server that is still under development.

The script requires a second parameter telling it where the directory is that should be mounted:

bash runTests-dev.sh 'php-solid-server' /path/to/php-solid-server

In comparison to the script it is based on, besides mounting a volume, this changes in this script:

• Add a shebang
• Add error options
• Add a wrapper function around the code so the script can also be sourced from other scripts
• Add a trap to stop the Docker container if the script only runs partially in case of errors
• Add a grep line to output the test results
• Change the docker rm call to a --rm flag on the docker run call
• Change the test runs from semi-duplicate lines to a for loop
• Remove the docker build step, as the used image is expected to already exist for development purposes