remove fixed versions

docker/logical-backup/Dockerfile

@@ -4,25 +4,25 @@ LABEL maintainer="Team ACID @ Zalando <team-acid@zalando.de>"
 SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 RUN apt-get update     \
     && apt-get install --no-install-recommends -y \
-        apt-utils=1.6.10 \
-        ca-certificates=20180409 \
-        lsb-release=9.20170808ubuntu1 \
-        pigz=2.4-1 \
-        python3-pip=9.0.1-2.3~ubuntu1 \
-        python3-setuptools=39.0.1-2 \
-        curl=7.58.0-2ubuntu3.7 \
-        jq=1.5+dfsg-2 \
-        gnupg=2.2.4-1ubuntu1.2 \
-    && pip3 install --no-cache-dir awscli==1.14.44 --upgrade \
+        apt-utils \
+        ca-certificates \
+        lsb-release \
+        pigz \
+        python3-pip \
+        python3-setuptools \
+        curl \
+        jq \
+        gnupg \
+    && pip3 install --no-cache-dir awscli --upgrade \
     && echo "deb http://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list \
     && cat /etc/apt/sources.list.d/pgdg.list \
     && curl --silent https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add - \
     && apt-get update \
     && apt-get install --no-install-recommends -y  \
-        postgresql-client-11=11.3-1.pgdg18.04+1    \
-        postgresql-client-10=10.8-1.pgdg18.04+1    \
-        postgresql-client-9.6=9.6.13-1.pgdg18.04+1 \
-        postgresql-client-9.5=9.5.17-1.pgdg18.04+1 \
+        postgresql-client-11  \
+        postgresql-client-10  \
+        postgresql-client-9.6 \
+        postgresql-client-9.5 \
     && apt-get clean \
     && rm -rf /var/lib/apt/lists/*