bump the number of executors on the jenkins build docker image
bump the number of executors on the jenkins build docker image

This image isn't configured to spawn extra workers, so just bump the
number of executors on the master instance so that certain jobs (which
trigger downstream jobs) will work.

gsehub/configuration,appsembler/configuration,arbrandes/edx-configuration,hks-epod/configuration,gsehub/configuration,arbrandes/edx-configuration,edx/configuration,gsehub/configuration,arbrandes/edx-configuration,mitodl/configuration,Stanford-Online/configuration,edx/configuration,rue89-tech/configuration,Stanford-Online/configuration,stvstnfrd/configuration,hks-epod/configuration,gsehub/configuration,rue89-tech/configuration,EDUlib/configuration,hks-epod/configuration,hks-epod/configuration,mitodl/configuration,edx/configuration,EDUlib/configuration,rue89-tech/configuration,stvstnfrd/configuration,gsehub/configuration,Stanford-Online/configuration,hks-epod/configuration,appsembler/configuration,mitodl/configuration,Stanford-Online/configuration,arbrandes/edx-configuration,Stanford-Online/configuration,rue89-tech/configuration,rue89-tech/configuration,arbrandes/edx-configuration,stvstnfrd/configuration,stvstnfrd/configuration,appsembler/configuration,EDUlib/configuration,appsembler/configuration,EDUlib/configuration,edx/configuration,stvstnfrd/configuration,mitodl/configuration,EDUlib/configuration