Install p7zip on DEPLOY=1 docker images and on MacOSX/Travis

On Ubuntu `7z` is available in the `p7zip-full` package.
On MacOSX it is in the `p7zip` formula.
On AppVeyor it is installed by default.

The `dist-*` and `cross` docker images build and deploy the dist
artifacts; the `x86_64-gnu-distcheck` docker image builds and checks
their sanity.

Author: ranma42

.travis.yml

@@ -95,7 +95,9 @@ matrix:
         MACOSX_DEPLOYMENT_TARGET=10.7
       os: osx
       osx_image: xcode7
-      install: *osx_install_sccache
+      install:
+        - brew install p7zip
+        - *osx_install_sccache
     - env: >
         RUST_CHECK_TARGET=dist
         RUST_CONFIGURE_ARGS="--target=aarch64-apple-ios,armv7-apple-ios,armv7s-apple-ios,i386-apple-ios,x86_64-apple-ios --enable-extended"
@@ -106,7 +108,9 @@ matrix:
         MACOSX_DEPLOYMENT_TARGET=10.7
       os: osx
       osx_image: xcode7
-      install: *osx_install_sccache
+      install:
+        - brew install p7zip
+        - *osx_install_sccache
 
     # "alternate" deployments, these are "nightlies" but don't have assertions
     # turned on, they're deployed to a different location primarily for projects
@@ -123,7 +127,9 @@ matrix:
         MACOSX_DEPLOYMENT_TARGET=10.7
       os: osx
       osx_image: xcode7
-      install: *osx_install_sccache
+      install:
+        - brew install p7zip
+        - *osx_install_sccache
 
 env:
   global:

src/ci/docker/cross/Dockerfile

@@ -10,6 +10,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   git \
   cmake \
   sudo \
+  p7zip-full \
   xz-utils \
   zlib1g-dev \
   g++-arm-linux-gnueabi \

src/ci/docker/dist-aarch64-linux/Dockerfile

@@ -23,6 +23,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   sudo \
   texinfo \
   wget \
+  p7zip-full \
   xz-utils \
   libssl-dev \
   pkg-config

src/ci/docker/dist-android/Dockerfile

@@ -16,6 +16,7 @@ RUN dpkg --add-architecture i386 && \
   openjdk-9-jre \
   sudo \
   libstdc++6:i386 \
+  p7zip-full \
   xz-utils \
   libssl-dev \
   pkg-config

src/ci/docker/dist-arm-linux/Dockerfile

@@ -23,6 +23,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   sudo \
   texinfo \
   wget \
+  p7zip-full \
   xz-utils \
   libssl-dev \
   pkg-config

src/ci/docker/dist-armhf-linux/Dockerfile

@@ -23,6 +23,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   sudo \
   texinfo \
   wget \
+  p7zip-full \
   xz-utils \
   libssl-dev \
   pkg-config

src/ci/docker/dist-armv7-linux/Dockerfile

@@ -23,6 +23,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   sudo \
   texinfo \
   wget \
+  p7zip-full \
   xz-utils \
   libssl-dev \
   pkg-config

src/ci/docker/dist-fuchsia/Dockerfile

@@ -11,6 +11,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   git \
   sudo \
   bzip2 \
+  p7zip-full \
   xz-utils \
   swig \
   libedit-dev \

src/ci/docker/dist-i586-gnu-i686-musl/Dockerfile

@@ -9,6 +9,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
+  p7zip-full \
   xz-utils \
   sudo \
   gdb \

src/ci/docker/dist-i686-freebsd/Dockerfile

@@ -11,6 +11,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   cmake \
   sudo \
   bzip2 \
+  p7zip-full \
   xz-utils \
   wget \
   libssl-dev \