Check to make sure there is not an alphanumeric character immeditely
before or after the 'flag'. It there is an alphanumeric character then
this is obviously not actually the flag we care about. For example if
the project declares a flag "valid-name" but the regex finds something
like "invalid_name" we should not match. Clearly this "invalid_name" is
not actually a wrong usage of the "valid-name" flag.
Before NodeName in the pod spec was used. Hence, pods with a fixed, pre-set
NodeName were never scheduled by the k8sm-scheduler, leading e.g. to a failing
e2e intra-pod test.
Fixesmesosphere/kubernetes-mesos#388