Cleanup dockerfiles and circle

Signed-off-by: Daniel Nephin <dnephin@docker.com>

circle.yml

@@ -4,7 +4,7 @@ jobs:
 
   lint:
     working_directory: /work
-    docker: [{image: 'docker:17.05-git'}]
+    docker: [{image: 'docker:17.06-git'}]
     steps:
       - checkout
       - setup_remote_docker:
@@ -22,7 +22,7 @@ jobs:
 
   cross:
     working_directory: /work
-    docker: [{image: 'docker:17.05-git'}]
+    docker: [{image: 'docker:17.06-git'}]
     parallelism: 3
     steps:
       - checkout
@@ -48,7 +48,7 @@ jobs:
 
   test:
     working_directory: /work
-    docker: [{image: 'docker:17.05-git'}]
+    docker: [{image: 'docker:17.06-git'}]
     steps:
       - checkout
       - setup_remote_docker:
@@ -75,9 +75,8 @@ jobs:
 
   validate:
     working_directory: /work
-    docker: [{image: 'docker:17.05-git'}]
+    docker: [{image: 'docker:17.06-git'}]
     steps:
-      - run: apk add -U git openssh
       - checkout
       - setup_remote_docker:
             reusable: true
@@ -93,7 +92,7 @@ jobs:
                 make -B vendor compose-jsonschema manpages yamldocs
   shellcheck:
     working_directory: /work
-    docker: [{image: 'docker:17.05-git'}]
+    docker: [{image: 'docker:17.06-git'}]
     steps:
       - checkout
       - setup_remote_docker

dockerfiles/Dockerfile.dev

@@ -4,21 +4,21 @@ FROM    golang:1.8.3-alpine
 RUN     apk add -U git make bash coreutils
 
 ARG     VNDR_SHA=9909bb2b8a0b7ea464527b376dc50389c90df587
-RUN     go get github.com/LK4D4/vndr && \
+RUN     go get -d github.com/LK4D4/vndr && \
         cd /go/src/github.com/LK4D4/vndr && \
         git checkout -q "$VNDR_SHA" && \
         go build -v -o /usr/bin/vndr . && \
         rm -rf /go/src/* /go/pkg/* /go/bin/*
 
 ARG     BINDATA_SHA=a0ff2567cfb70903282db057e799fd826784d41d
-RUN     go get github.com/jteeuwen/go-bindata/go-bindata && \
+RUN     go get -d github.com/jteeuwen/go-bindata/go-bindata && \
         cd /go/src/github.com/jteeuwen/go-bindata/go-bindata && \
         git checkout -q "$BINDATA_SHA" && \
         go build -v -o /usr/bin/go-bindata . && \
         rm -rf /go/src/* /go/pkg/* /go/bin/*
 
 ARG     FILEWATCHER_SHA=2e12ea42f6c8c089b19e992145bb94e8adaecedb
-RUN     go get github.com/dnephin/filewatcher && \
+RUN     go get -d github.com/dnephin/filewatcher && \
         cd /go/src/github.com/dnephin/filewatcher && \
         git checkout -q "$FILEWATCHER_SHA" && \
         go build -v -o /usr/bin/filewatcher . && \

dockerfiles/Dockerfile.lint

@@ -3,7 +3,7 @@ FROM    golang:1.8.3-alpine
 RUN     apk add -U git
 
 ARG     GOMETALINTER_SHA=4306381615a2ba2a207f8fcea02c08c6b2b0803f
-RUN     go get github.com/alecthomas/gometalinter && \
+RUN     go get -d github.com/alecthomas/gometalinter && \
         cd /go/src/github.com/alecthomas/gometalinter && \
         git checkout -q "$GOMETALINTER_SHA" && \
         go build -v -o /usr/local/bin/gometalinter . && \