Update Dockerfile

Dockerfile

-FROM debian:8.5
+FROM debian
 
-RUN apt-get clean && rm -rf /var/lib/apt/lists/* && apt-get clean
-RUN echo "deb http://deb.debian.org/debian unstable main" | tee -a /etc/apt/sources.list
-RUN echo "deb http://deb.debian.org/debian-debug unstable-debug main" | tee -a /etc/apt/sources.list
-RUN echo "deb http://deb.debian.org/debian-ports unstable main" | tee -a /etc/apt/sources.list
-RUN echo "deb http://ftp.ports.debian.org/debian-ports unreleased main" | tee -a /etc/apt/sources.list
-RUN echo "deb http://ftp.ports.debian.org/debian-ports unstable main" | tee -a /etc/apt/sources.list
-
- 
-RUN add-apt-repository ppa:webupd8team/y-ppa-manager && apt-get update && apt-get install -y y-ppa-manager && y-ppa-manager
-
-RUN apt-get install -y debian-archive-keyring
-RUN apt-get update && apt-get install -y wget gnupg && apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 40976EAF437D05B5 && gpg --keyserver pgp.mit.edu --recv-keys 1F41B907 && gpg --armor --export 1F41B907 | apt-key add -
-RUN wget -O - https://www.ports.debian.org/archive_2016.key | apt-key add -
-RUN apt-get update && apt-get install -y fping gdebi p7zip-full --fix-missing 
+RUN apt-get update && apt-get install -y wget gnupg fping gdebi p7zip-full --fix-missing 
 RUN apt-get install -y libqtgui4 libqt4-network libqt4-xml libqt4-xmlpatterns libqt4-script --fix-missing
 RUN apt-get install -y lib32z1 lib32ncurses5 lib32stdc++6 --fix-missing
 RUN wget -O /platformflashtoollite_5.8.4.0_linux_x86_64.deb https://download.01.org/android-ia/tools/platformflashtool-lite/5.8.4.0/platformflashtoollite_5.8.4.0_linux_x86_64.deb