circleci: upgrade to 1.13

.circleci/config.yml

@@ -1,9 +1,9 @@
 version: 2.1
 jobs:
-  build_1_12:
+  build_1_13:
     docker:
       # Find these on https://hub.docker.com/r/circleci/golang/
-      - image: circleci/golang:1.12.9
+      - image: circleci/golang:1.13.0
     steps:
       - checkout
       # This step caches your modules directory.  Find out more about how to cache modules from
@@ -23,6 +23,27 @@ jobs:
           key: go-mod-v1-sum-{{ checksum "go.sum" }}
           paths:
             - "/go/pkg/mod"
+  build_1_12:
+    docker:
+      # Find these on https://hub.docker.com/r/circleci/golang/
+      - image: circleci/golang:1.12.9
+    steps:
+      - checkout
+      # This step caches your modules directory.  Find out more about how to cache modules from
+      # https://circleci.com/blog/go-v1.11-modules-and-circleci/
+      - restore_cache:
+          keys:
+            # Keys should be of a format (thing)-(cache_version)-(hash)
+            # This is thing="go modules" cache_version="1" and hash "checksum of go.sum file"
+            - go-mod-v1-sum-{{ checksum "go.sum" }}
+            - go-mod-v1-sum-
+      - run: go mod download
+      - run: go mod verify
+      - run: make build test
+      - save_cache:
+          key: go-mod-v1-sum-{{ checksum "go.sum" }}
+          paths:
+            - "/go/pkg/mod"
   # Comments and rational for this build block are the same as the above
   build_1_11:
     docker:
@@ -47,4 +68,5 @@ workflows:
   build:
     jobs:
       - build_1_11
-      - build_1_12
+      - build_1_12
+      - build_1_13

go.mod

@@ -2,4 +2,4 @@ module github.com/cep21/gotemplate
 
 go 1.12
 
-require github.com/golangci/golangci-lint v1.17.1
+require github.com/golangci/golangci-lint v1.18.0