[CircleCI] Change runner type (#1822)

s/gpu.medium/gpu.nvidia.small/
And for shards 3 and  13 set resource class to `gpu.nvidia.small.multi`:

As an old ones are no longer available

Author: malfet

.circleci/config.yml

@@ -173,7 +173,7 @@ pytorch_tutorial_build_worker_defaults: &pytorch_tutorial_build_worker_defaults
   environment:
     DOCKER_IMAGE: "308535385114.dkr.ecr.us-east-1.amazonaws.com/pytorch/pytorch-linux-xenial-cuda10.2-cudnn7-py3-gcc7"
     CUDA_VERSION: "9"
-  resource_class: gpu.medium
+  resource_class: gpu.nvidia.small
   <<: *pytorch_tutorial_build_defaults
 
 pytorch_tutorial_build_manager_defaults: &pytorch_tutorial_build_manager_defaults
@@ -223,6 +223,7 @@ jobs:
 
   pytorch_tutorial_pr_build_worker_3:
     <<: *pytorch_tutorial_build_worker_defaults
+    resource_class: gpu.nvidia.small.multi
 
   pytorch_tutorial_pr_build_worker_4:
     <<: *pytorch_tutorial_build_worker_defaults
@@ -253,12 +254,14 @@ jobs:
 
   pytorch_tutorial_pr_build_worker_13:
     <<: *pytorch_tutorial_build_worker_defaults
+    resource_class: gpu.nvidia.small.multi
 
   pytorch_tutorial_pr_build_worker_14:
     <<: *pytorch_tutorial_build_worker_defaults
 
   pytorch_tutorial_pr_build_worker_15:
     <<: *pytorch_tutorial_build_worker_defaults
+    resource_class: gpu.nvidia.medium
 
   pytorch_tutorial_pr_build_worker_16:
     <<: *pytorch_tutorial_build_worker_defaults