Update remote_docker version in CircleCI config

20.10.17 is the current default.

.circleci/config.yml

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 6d6b89d..2bfda2a 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -141,7 +141,7 @@
           name: install docker
           command: apt-get update -q && apt-get install -q -y docker.io
       - setup_remote_docker:
-          version: 19.03.13
+          version: 20.10.17
       # Build and test the tip-of-tree build of EMSDK
       - run:
           name: build
@@ -158,7 +158,7 @@
           name: install docker
           command: apt-get update -q && apt-get install -q -y docker.io
       - setup_remote_docker:
-          version: 19.03.13
+          version: 20.10.17
       - run:
           name: build
           command: make -C ./docker version=${CIRCLE_TAG} build