resolve dynamic networks on infrastructure settings

Signed-off-by: dmitriy kalinin <dmitriy@pivotallabs.com>
introduce SshResult as ssh action return value

Signed-off-by: dmitriy kalinin <dmitriy@pivotallabs.com>
use inf settings to resolve dynamic networks in apply spec

Signed-off-by: dmitriy kalinin <dmitriy@pivotallabs.com>
log failure to resolve default network in settings service

Signed-off-by: dmitriy kalinin <dmitriy@pivotallabs.com>
use logger.Error when logging errors

Signed-off-by: dmitriy kalinin <dmitriy@pivotallabs.com>