build.sh: This script will build dependencies, then build ewoms and execute its tests. It also inspects the $ghbPrBuildComment environmental variable and builds downstreams if requested. It inspects the $ghbPrBuildComment environmental variable to obtain a pull request to use for the modules.
It is intended for pre-merge builds of pull requests.
To specify a given pull request to use for upstreams and downstreams, trigger line needs to contain <module-name>=<pull request number>.
To build with downstreams the trigger line needs to contain 'with downstreams'.