Add ability to use with kubernetes configmaps

[ayenter]

Kubernetes configmaps place files in hidden folders and use symlinks to these files. Using a traditional find command will return the absolute path to the file (which is an undesired path), instead of the symlink (desired path). This pr will update the *.proto file find command to return all files AND SYMLINKS that are not in a hidden folder.

Ex:

$ ls -al protos
  drwxr-xr-x    1 root     root          4096 Aug  8 21:35 .
  drwxr-xr-x    1 root     root          4096 Aug  8 19:17 ..
  -rw-r--r--    1 root     root          3708 Aug  8 19:18 protos/my.proto
$ kubectl create configmap my-protos --from-file=protos/
$ kubectl create -f deploy.yaml
$ kubectl exec -it container /bin/bash
# ls -al /opt/generator/protos
  drwxrwxrwx    3 root     root          4096 Aug  8 19:46 .
  drwxr-xr-x    3 root     root          4096 Aug  8 20:02 ..
  drwxr-xr-x    2 root     root          4096 Aug  8 19:46 ..2018_08_08_19_46_03.335203197
  lrwxrwxrwx    1 root     root            31 Aug  8 19:46 ..data -> ..2018_08_08_19_46_03.335203197
  lrwxrwxrwx    1 root     root            20 Aug  8 19:46 my.proto -> ..data/my.proto