Add python3 to dependencies in darwin-x64 and darwin-x86 Dockerfiles

Author: elgatito

docker/darwin-x64.Dockerfile

@@ -12,9 +12,11 @@ RUN apt-get install -y --force-yes apt-utils apt-transport-https libcurl4-openss
 RUN echo "deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch-4.0 main" >> /etc/apt/sources.list && \
     wget --no-check-certificate -qO - http://apt.llvm.org/llvm-snapshot.gpg.key | apt-key add - && \
     apt-get update && \
-    apt-get install -y --force-yes clang-4.0 llvm-4.0-dev automake autogen \
-                                   libtool libxml2-dev uuid-dev libssl-dev bash \
-                                   patch make tar xz-utils bzip2 gzip sed cpio git zlib1g-dev
+    apt-get install -y --force-yes \
+        clang-4.0 llvm-4.0-dev automake autogen \
+        libtool libxml2-dev uuid-dev libssl-dev bash \
+        patch make tar xz-utils bzip2 gzip sed cpio git zlib1g-dev \
+        python3
 
 RUN curl -L https://github.com/tpoechtrager/osxcross/archive/master.tar.gz | tar xz && \
     cd /osxcross-master/ && \

docker/darwin-x86.Dockerfile

@@ -11,9 +11,11 @@ RUN apt-get install -y --force-yes apt-utils apt-transport-https libcurl4-openss
 RUN echo "deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch-4.0 main" >> /etc/apt/sources.list && \
     wget --no-check-certificate -qO - http://apt.llvm.org/llvm-snapshot.gpg.key | apt-key add - && \
     apt-get update && \
-    apt-get install -y --force-yes clang-4.0 llvm-4.0-dev automake autogen \
-                                   libtool libxml2-dev uuid-dev libssl-dev bash \
-                                   patch make tar xz-utils bzip2 gzip sed cpio git zlib1g-dev
+    apt-get install -y --force-yes \
+        clang-4.0 llvm-4.0-dev automake autogen \
+        libtool libxml2-dev uuid-dev libssl-dev bash \
+        patch make tar xz-utils bzip2 gzip sed cpio git zlib1g-dev \
+        python3
 
 RUN curl -L https://github.com/tpoechtrager/osxcross/archive/master.tar.gz | tar xz && \
     cd /osxcross-master/ && \