Merge pull request #5653 from hypothesis/update-alpine2

Update to Alpine Linux 3.10

Dockerfile

@@ -15,12 +15,11 @@ COPY h/static ./h/static
 RUN npm run build
 
 # Stage 2: Build the rest of the app using the build output from Stage 1.
-FROM alpine:3.9.4
+FROM python:3.6.9-alpine3.10
 LABEL maintainer="Hypothes.is Project and contributors"
 
 # Install system build and runtime dependencies.
 RUN apk add --no-cache \
-    ca-certificates \
     collectd \
     collectd-disk \
     collectd-nginx \
@@ -54,7 +53,6 @@ RUN apk add --no-cache --virtual build-deps \
     build-base \
     libffi-dev \
     postgresql-dev \
-    python-dev \
   && pip install --no-cache-dir -U pip \
   && pip install --no-cache-dir -r requirements.txt \
   && apk del build-deps