fix(deisctl): unit test should also use main version package

The deisctl unit tests broke when #2777 was merged, but we didn't catch it because they were not wired into the test-integration.sh script. They are now, and this change fixes this unit test error:
```console
$ make -C deisctl/ test-unit
godep go test -v -cover ./...
# github.com/deis/deis/deisctl
./deisctl_test.go:57: undefined: Version
FAIL	github.com/deis/deis/deisctl [build failed]
```