ci: restore docker files

scripts/docker/ubuntu-arm/Dockerfile

@@ -0,0 +1,45 @@
+FROM ubuntu:14.04
+WORKDIR /build
+
+# install tools and dependencies
+RUN apt-get -y update && \
+        apt-get install -y --force-yes --no-install-recommends \
+        curl git make g++ gcc-arm-linux-gnueabihf g++-arm-linux-gnueabihf \
+        libc6-dev-armhf-cross wget file ca-certificates \
+        binutils-arm-linux-gnueabihf cmake3 libudev-dev \
+        && \
+    apt-get clean
+
+# install rustup
+RUN curl https://sh.rustup.rs -sSf | sh -s -- -y
+
+# rustup directory
+ENV PATH /root/.cargo/bin:$PATH
+
+ENV RUST_TARGETS="arm-unknown-linux-gnueabihf"
+
+# multirust add arm--linux-gnuabhf toolchain
+RUN rustup target add armv7-unknown-linux-gnueabihf
+
+# show backtraces
+ENV RUST_BACKTRACE 1
+
+# show tools
+RUN rustc -vV && cargo -V
+
+# build parity
+ADD . /build/parity
+RUN cd parity && \
+        mkdir -p .cargo && \
+        echo '[target.armv7-unknown-linux-gnueabihf]\n\
+        linker = "arm-linux-gnueabihf-gcc"\n'\
+        >>.cargo/config && \
+        cat .cargo/config && \
+        cargo build --target armv7-unknown-linux-gnueabihf --release --verbose && \
+        ls /build/parity/target/armv7-unknown-linux-gnueabihf/release/parity && \
+        /usr/bin/arm-linux-gnueabihf-strip /build/parity/target/armv7-unknown-linux-gnueabihf/release/parity
+
+RUN file /build/parity/target/armv7-unknown-linux-gnueabihf/release/parity
+
+EXPOSE 8080 8545 8180
+ENTRYPOINT ["/build/parity/target/armv7-unknown-linux-gnueabihf/release/parity"]