private static boolean propMatchesPrefix(String prefix, String key) {
        return key.startsWith(prefix) && key.length() >= prefix.length();
    }
Calculate the duration between now and the given time

Taken mostly from http://stackoverflow.com/a/5062810/207604 . Kudos to @dblevins

@param start starting time (in milliseconds)
@return time in seconds
src/main/java/io/fabric8/maven/docker/util/EnvUtil.java