update base image

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

atom/Dockerfile

@@ -19,7 +19,7 @@
 #
 
 # Base docker image
-FROM debian:stretch-slim
+FROM debian:buster-slim
 
 LABEL maintainer "Jessie Frazelle <jess@linux.com>"
 
@@ -47,7 +47,6 @@ RUN apt-get update && apt-get install -y \
 	libasound2 \
 	libcap2 \
 	libgconf-2-4 \
-	libgnome-keyring-dev \
 	libgtk2.0-0 \
 	libnotify4 \
 	libnss3 \

skype/Dockerfile

@@ -10,7 +10,7 @@
 #	--name skype \
 #	jess/skype
 #
-FROM debian:jessie-slim
+FROM debian:buster-slim
 
 # Tell debconf to run in non-interactive mode
 ENV DEBIAN_FRONTEND noninteractive
@@ -19,6 +19,7 @@ RUN apt-get update && apt-get install -y \
 	apt-transport-https \
 	ca-certificates \
 	curl \
+	gnupg \
 	--no-install-recommends
 
 # Add the skype debian repo