Single page application hoster

Every web application of MaCySTe is hosted via the spa-hoster component. This component serves static files under a directory specified with the environment variable STATIC_FILES_PATH.
It can be binded on a specific port thanks to BIND_PORT environment variable.
spa-hoster exposes environment variables at path /config/env/<ENV_NAME> BEWARE that this may not be safe because it exposes all the env, but you can specify which variables to serve via a space separated list in another environment variable named ENV_WHITELIST.