update Dockerfiles, remove Travis

docker/Dockerfile

-FROM aberaud/opendht-deps
+FROM ghcr.io/savoirfairelinux/opendht/opendht-deps:latest
 LABEL maintainer="Adrien Béraud <adrien.beraud@savoirfairelinux.com>"
+LABEL org.opencontainers.image.source https://github.com/savoirfairelinux/opendht
 
 RUN git clone https://github.com/savoirfairelinux/opendht.git \
 	&& cd opendht && mkdir build && cd build \

docker/DockerfileBionic

-FROM docker.pkg.github.com/savoirfairelinux/opendht/opendht-deps-bionic:latest
+FROM ghcr.io/savoirfairelinux/opendht/opendht-deps-bionic:latest
 LABEL maintainer="Adrien Béraud <adrien.beraud@savoirfairelinux.com>"
+LABEL org.opencontainers.image.source https://github.com/savoirfairelinux/opendht
 
 RUN git clone https://github.com/savoirfairelinux/opendht.git \
 	&& cd opendht && mkdir build && cd build \

docker/DockerfileDeps

 FROM ubuntu:20.04
 LABEL maintainer="Adrien Béraud <adrien.beraud@savoirfairelinux.com>"
+LABEL org.opencontainers.image.source https://github.com/savoirfairelinux/opendht
 
 RUN apt-get update && apt-get install -y \
         dialog apt-utils \

docker/DockerfileDepsBionic

 FROM ubuntu:18.04
 LABEL maintainer="Adrien Béraud <adrien.beraud@savoirfairelinux.com>"
+LABEL org.opencontainers.image.source https://github.com/savoirfairelinux/opendht
 
 RUN echo "APT::Acquire::Retries \"3\";" > /etc/apt/apt.conf.d/80-retries
 RUN apt-get update && apt-get install -y \

docker/DockerfileDepsLlvm

 FROM ubuntu:20.04
 LABEL maintainer="Adrien Béraud <adrien.beraud@savoirfairelinux.com>"
+LABEL org.opencontainers.image.source https://github.com/savoirfairelinux/opendht
 
 RUN apt-get update && apt-get install -y \
         dialog apt-utils \

docker/DockerfileLlvm

-FROM aberaud/opendht-deps-llvm
+FROM ghcr.io/savoirfairelinux/opendht/opendht-deps-llvm:latest
 LABEL maintainer="Adrien Béraud <adrien.beraud@savoirfairelinux.com>"
+LABEL org.opencontainers.image.source https://github.com/savoirfairelinux/opendht
 
 RUN git clone https://github.com/savoirfairelinux/opendht.git \
 	&& cd opendht && mkdir build && cd build \

docker/DockerfileTravis

-FROM aberaud/opendht-deps-bionic
-LABEL maintainer="Adrien Béraud <adrien.beraud@savoirfairelinux.com>"
-
-RUN apt-get update && apt-get install -y python3-pip && pip3 install --upgrade cmake
-
-COPY . /root/opendht
-RUN cd /root/opendht && mkdir build && cd build \
-	&& cmake -DCMAKE_INSTALL_PREFIX=/usr -DOPENDHT_PYTHON=On -DOPENDHT_C=On -DOPENDHT_LTO=On -DOPENDHT_TESTS=ON ..  \
-	&& make -j8 && ./opendht_unit_tests && make install

docker/DockerfileTravisLlvm

-FROM aberaud/opendht-deps-llvm
-LABEL maintainer="Adrien Béraud <adrien.beraud@savoirfairelinux.com>"
-
-COPY . /root/opendht
-RUN cd /root/opendht && mkdir build && cd build \
-	&& cmake -DCMAKE_INSTALL_PREFIX=/usr -DOPENDHT_PYTHON=On -DOPENDHT_C=On -DOPENDHT_TESTS=ON .. \
-	&& make -j8 && ./opendht_unit_tests && make install

docker/DockerfileTravisProxy

-FROM aberaud/opendht-deps
-LABEL maintainer="Adrien Béraud <adrien.beraud@savoirfairelinux.com>"
-
-COPY . /root/opendht