Update Alpine version, install requirements for python cryptography package

.dockerignore

+venv
+clusters
+docs

Dockerfile

-FROM alpine:3.9
+FROM alpine:3.12
 
 LABEL name="OpenAppStack management"
 LABEL version="4.0"
 LABEL vendor1="Greenhost"
 
 RUN apk --no-cache add \
+  cargo \
   chromium \
   chromium-chromedriver \
   curl \
@@ -17,9 +18,11 @@ RUN apk --no-cache add \
   musl-dev \
   openssh-client \
   openssl-dev \
+  py3-pip \
   python3-dev \
-  rsync
+  rsync \
+  rust
 
 COPY ./requirements.txt /requirements.txt
-RUN pip3 install -r /requirements.txt
+RUN pip install -r /requirements.txt
 RUN ln -s /usr/bin/python3 /usr/bin/python