chore(rootfs/Dockerfile): upgrade to glide 0.10.2

Author: mboersma

rootfs/Dockerfile

@@ -1,9 +1,6 @@
 FROM golang:1.6.0
 
-ENV GO15VENDOREXPERIMENT=1
-ENV GLIDE_HOME=/root
-
-WORKDIR /tmp
+ENV GLIDE_VERSION=0.10.2 GLIDE_HOME=/root GO15VENDOREXPERIMENT=1
 
 RUN apt-get update && apt-get install -y \
   jq \
@@ -12,9 +9,8 @@ RUN apt-get update && apt-get install -y \
   zip \
   --no-install-recommends \
   && rm -rf /var/lib/apt/lists/* \
-  && curl -L https://github.com/Masterminds/glide/releases/download/0.10.1/glide-0.10.1-linux-amd64.tar.gz | tar xvz \
-  && mv linux-amd64/glide /usr/local/bin/ \
-  && rm -rf linux-amd64 \
+  &&  curl -sSL https://github.com/Masterminds/glide/releases/download/$GLIDE_VERSION/glide-$GLIDE_VERSION-linux-amd64.tar.gz \
+    | tar -vxz -C /usr/local/bin --strip=1 \
   && curl -L https://s3-us-west-2.amazonaws.com/get-deis/shellcheck-0.4.3-linux-amd64 -o /usr/local/bin/shellcheck \
   && chmod +x /usr/local/bin/shellcheck \
   && go get -u -v \