Enable lint on go1.7

.travis.yml

@@ -3,7 +3,7 @@ sudo: false
 go:
   - 1.5
   - 1.6
-  - 1.7rc6
+  - 1.7
   - tip
 env:
   global:

Makefile

@@ -9,7 +9,7 @@ PKG_FILES ?= *.go spy benchmarks zwrap zbark testutils
 # stable release.
 GO_VERSION := $(shell go version | cut -d " " -f 3)
 GO_MINOR_VERSION := $(word 2,$(subst ., ,$(GO_VERSION)))
-LINTABLE_MINOR_VERSIONS := 6
+LINTABLE_MINOR_VERSIONS := 7
 ifneq ($(filter $(LINTABLE_MINOR_VERSIONS),$(GO_MINOR_VERSION)),)
 SHOULD_LINT := true
 endif
@@ -33,6 +33,8 @@ else
 	@echo "Not installing golint, since we don't expect to lint on" $(GO_VERSION)
 endif
 
+VET_SKIP_ERRORF=grep -v -e "possible formatting directive in Error call"
+
 .PHONY: lint
 lint:
 ifdef SHOULD_LINT
@@ -42,7 +44,7 @@ ifdef SHOULD_LINT
 	@echo "Installing test dependencies for vet..."
 	@go test -i $(PKGS)
 	@echo "Checking vet..."
-	@$(foreach dir,$(PKG_FILES),go tool vet $(dir) 2>&1 | tee -a lint.log;)
+	@$(foreach dir,$(PKG_FILES),go tool vet $(dir) 2>&1 | $(VET_SKIP_ERRORF) | tee -a lint.log;)
 	@echo "Checking lint..."
 	@$(foreach dir,$(PKGS),golint $(dir) 2>&1 | tee -a lint.log;)
 	@echo "Checking for unresolved FIXMEs..."