Added virualenv package

docker/Dockerfile

@@ -10,7 +10,8 @@ RUN apt-get update && \
     apt-get install -q -y --no-install-recommends \
     software-properties-common \
     python-software-properties \
-    python-pip python-dev \
+    python-pip \
+    python-dev \
     libxml2-dev \
     libxslt1-dev \
     zlib1g-dev \
@@ -20,7 +21,8 @@ RUN apt-get update && \
     libsasl2-dev \
     libldap2-dev \
     npm git \
-    python-virtualenv && \
+    python-virtualenv \
+    virtualenv && \
     apt-get clean  && \
     rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*