Update Dockerfile: fixing right python version

6 jobs for master in 16 minutes and 37 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #7639
build:json

00:00:14

passed #7638
build:pytorch

00:01:17

 
  Test
passed #7640
test:json

00:00:35

 
  Push
passed #7641
push:all

00:14:18

passed #7642
push:hub

00:02:59

 
  Deploy
passed #7643
deploy:json

00:00:26