install libwx widgets dependencies for observer app

the most popular GUI app based on wx ? and the only one?
 for #28; image size increased ~65MB, is it worth it?

REPOSITORY    TAG                   IMAGE ID      CREATED             SIZE
otp           20.0-rc0-cd48b81-wx   f8b3e0fc15dd  49 seconds ago      814.9 MB
otp           20.0-rc0-cd48b81      dbff7d029fed  About an hour ago   749.9 MB

20/Dockerfile

@@ -8,9 +8,13 @@ RUN set -xe \
 	&& OTP_DOWNLOAD_URL="https://github.com/erlang/otp/archive/${OTP_VERSION##*@}.tar.gz" \
 	&& OTP_DOWNLOAD_SHA256="e9aad78742359fca12c20eaf9d90ba566dda96673506d7a0f2f2b67db47e3be0" \
 	&& runtimeDeps='libodbc1 \
-			libsctp1' \
+			libsctp1 \
+			libwxbase3.0-0 \
+			libwxgtk3.0-0' \
 	&& buildDeps='unixodbc-dev \
-			libsctp-dev' \
+			libsctp-dev \
+			libwxbase3.0-dev \
+			libwxgtk3.0-dev' \
 	&& apt-get update \
 	&& apt-get install -y --no-install-recommends $runtimeDeps \
 	&& apt-get install -y --no-install-recommends $buildDeps \