Optimize Dockerfile.ci with Docker best practices

Dockerfile.ci

@@ -2,8 +2,12 @@ FROM python:3.7-buster
 
 LABEL maintainer="contact@jailbreak.paris"
 
-RUN apt-get update
-RUN apt-get install -y python3-dev wget openssh-client sqlite3 csvkit
+RUN apt-get update && apt-get install --yes --no-install-recommends \
+    csvkit \
+    openssh-client \
+    python3-dev \
+    sqlite3 \
+    wget
 
 COPY requirements.txt .
-RUN pip install -r requirements.txt
+RUN pip install --no-cache-dir --requirement requirements.txt