Add varcheck to presubmit.

.travis.yml

@@ -8,6 +8,7 @@ go:
 before_install:
   - source ./bin/consider-early-travis-exit.sh
   - sudo apt-get install tree
+  - go get -u github.com/opennota/check/cmd/varcheck
   - go get -u github.com/golang/lint/golint
   - go get -u golang.org/x/tools/cmd/goimports
   - go get -u github.com/onsi/ginkgo/ginkgo

bin/pre-commit.sh

@@ -41,14 +41,14 @@ function testGoLint {
   diff -u <(echo -n) <(go_dirs | xargs -0 golint --min_confidence 0.85 )
 }
 
+# Not using the 'goimports' check because it reports hyphens in imported
+# package names as errors, and we vendor in packages that have
+# hyphens in their names.
 function testGoMetalinter {
   diff -u <(echo -n) <(go_dirs | xargs -0 gometalinter.v2 --disable-all --deadline 5m \
   --enable=misspell \
   --enable=structcheck \
   --enable=deadcode \
-# Disabling 'goimports' because it reports hyphens in imported package \
-# names as errors, and we have to vendor them in regardless. \
-#  --enable=goimports \
   --enable=varcheck \
   --enable=goconst \
   --enable=unparam \
@@ -60,7 +60,6 @@ function testGoMetalinter {
   --dupl-threshold=400 --enable=dupl)
 }
 
-
 function testGoVet {
   go vet -all ./...
 }