Fix circle build

Author: databus23

.circleci/config.yml

@@ -2,7 +2,7 @@ version: 2
 jobs:
   build:
     docker:
-      - image: circleci/golang:1.10
+      - image: circleci/golang:1.13
     working_directory: /go/src/github.com/databus23/helm-diff
     steps:
       - checkout

Makefile

@@ -42,6 +42,7 @@ ifndef HAS_GLIDE
 	go get -u github.com/Masterminds/glide
 endif
 	glide install --strip-vendor
+	command -v golint || go get -u golang.org/x/lint/golint
 
 .PHONY: docker-run-release
 docker-run-release: export pkg=/go/src/github.com/databus23/helm-diff