Change isnumberic to isdigit for Py2.7 compat
Change isnumberic to isdigit for Py2.7 compat

isnumeric is Py3.x only, change to isdigit for Py2.7 compat.
We still need to be compatible to 2.x Python versions.

Signed-off-by: Christoph Kassen <21a19229d09eaaba535d395ba11b820b0886ba87@telekom.de>

TelekomCloud/pony-express