Adjust Travis to also compile, to test that compilation still succeeds

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)

.travis.yml

@@ -11,7 +11,8 @@ go: 1.2.1
 sudo: false
 
 # Disable the normal go build.
-install: true
+install:
+  - export DOCKER_BUILDTAGS='exclude_graphdriver_btrfs exclude_graphdriver_devicemapper' # btrfs and devicemapper fail to compile thanks to a couple missing headers (which we can't install thanks to "sudo: false")
 
 before_script:
   - env | sort
@@ -19,5 +20,6 @@ before_script:
 script:
   - hack/make.sh validate-dco
   - hack/make.sh validate-gofmt
+  - AUTO_GOPATH=1 ./hack/make.sh dynbinary
 
 # vim:set sw=2 ts=2: