Update Docker image to Alpine 3.12

Dockerfile

@@ -1,16 +1,18 @@
-FROM dock.mau.dev/tulir/lottieconverter:alpine-3.11
+FROM dock.mau.dev/tulir/lottieconverter:alpine-3.12
 
-RUN echo "@edge_main http://dl-cdn.alpinelinux.org/alpine/edge/main" >> /etc/apk/repositories
 RUN echo "@edge_testing http://dl-cdn.alpinelinux.org/alpine/edge/testing" >> /etc/apk/repositories
 RUN echo "@edge_community http://dl-cdn.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories
 
 RUN apk add --no-cache \
+      python3 py3-pip py3-setuptools py3-wheel \
       py3-virtualenv \
       py3-pillow \
       py3-aiohttp \
       py3-magic \
       py3-sqlalchemy \
+      py3-telethon-session-sqlalchemy@edge_testing \
       py3-alembic@edge_testing \
+        py3-python-editor@edge_community \
       py3-psycopg2 \
       py3-ruamel.yaml \
       py3-commonmark@edge_testing \
@@ -22,8 +24,7 @@ RUN apk add --no-cache \
         py3-requests \
         #imageio
           py3-numpy \
-      #telethon
-        py3-rsa \
+      py3-telethon@edge_testing \
         # Optional for socks proxies
         py3-pysocks \
         # cryptg
@@ -35,19 +36,18 @@ RUN apk add --no-cache \
       su-exec \
       netcat-openbsd \
       # olm
-      olm-dev@edge_community \
+      olm-dev \
       # matrix-nio?
       py3-future \
       py3-atomicwrites \
-      py3-pycryptodome@edge_main \
-      py3-peewee@edge_community \
-      py3-pyrsistent@edge_community \
+      py3-pycryptodome \
+      py3-peewee \
+      py3-pyrsistent \
       py3-jsonschema \
-      py3-aiofiles \
-      py3-cachetools@edge_community \
-      py3-prometheus-client@edge_community \
+      #py3-aiofiles \ # (too new)
+      py3-cachetools \
       py3-unpaddedbase64 \
-      py3-pyaes@edge_testing \
+      py3-h2@edge_testing \
       py3-logbook@edge_testing
 
 COPY requirements.txt /opt/mautrix-telegram/requirements.txt