UDockerfile: Cleaning cache before the installation of deb packages

ubuntu_client/Dockerfile

@@ -31,8 +31,8 @@ RUN apt-get install -y git gdebi-core libcurl4 \
 						libzmq5 libdw-dev libbz2-dev \
 						heimdal-servers krb5-kdc krb5-admin-server \
 						krb5-user libpam-krb5 libpam-ccreds auth-client-config \
-#In ubuntu 18.04 initscripts network manager has changed- obsolete 						
-#less has a foreign repo check it later
+						#In ubuntu 18.04 initscripts network manager has changed- obsolete 						
+						#less has a foreign repo check it laterable
 						nano parallel fort77 gcc gfortran-8 gdb g++ perl \
 						libacl1-dev bzip2 automake autoconf libtool wget curl davix \
 						cadaver
@@ -53,6 +53,7 @@ RUN wget https://cmake.org/files/v3.11/cmake-3.11.4.tar.gz
 RUN tar -xf cmake-3.11.4.tar.gz
 RUN cd ./cmake-3.11.4 && ./bootstrap && make && make install
 
+RUN apt-get clean
 RUN apt-get update
 RUN apt-get install -y eos-client eos-fusex xrootd-client-dbgsym xrootd-client-devel-dbgsym \
 						xrootd-client-devel xrootd-client-libs-dbgsym xrootd-client-libs \