Add stable Dockerfile for CentOS 7

docker/stable/centos7/Dockerfile

@@ -0,0 +1,36 @@
+FROM centos:7
+MAINTAINER Andrew Schwartzmeyer <andschwa@microsoft.com>
+
+ARG POWERSHELL_RELEASE=v6.0.0-alpha.9
+ARG POWERSHELL_PACKAGE=powershell-6.0.0_alpha.9-1.el7.centos.x86_64.rpm
+
+# Setup the locale
+ENV LANG en_US.UTF-8
+ENV LC_ALL $LANG
+RUN localedef --charmap=UTF-8 --inputfile=en_US $LANG
+
+# Install dependencies and clean up
+RUN yum install -y \
+        glibc \
+        libcurl \
+        ca-certificates \
+        libgcc \
+        libicu \
+        openssl \
+        libstdc++ \
+        ncurses-base \
+        libunwind \
+        uuid \
+        zlib \
+        which \
+        curl \
+        git \
+    && yum clean all
+
+# Install PowerShell package and clean up
+RUN curl -SLO https://github.com/PowerShell/PowerShell/releases/download/$POWERSHELL_RELEASE/$POWERSHELL_PACKAGE \
+    && yum install -y $POWERSHELL_PACKAGE \
+    && rm $POWERSHELL_PACKAGE
+
+# Use array to avoid Docker prepending /bin/sh -c
+ENTRYPOINT [ "powershell" ]