Fix Travis config

.travis.yml

@@ -1,6 +1,10 @@
 language: go
 sudo: false
 
+env:
+  global:
+    - GO111MODULE=on
+
 go:
 - 1.12.x
 - master

Makefile

@@ -90,15 +90,11 @@ ifndef HAS_GO
 endif
 
 .PHONY: go-dependencies
-HAS_DEP := $(shell which dep)
 go-dependencies: ## Ensure build dependencies
 	@echo "+ $@"
 	@echo "Ensure Golang runtime dependencies"
 	go mod vendor -v
 
-.PHONY: dep
-dep: go-dependencies ## Ensure build dependencies
-
 .PHONY: build
 build: $(NAME) ## Builds a dynamic executable or package
 	@echo "+ $@"