diff --git a/.golangci.toml b/.golangci.toml
index 125fd8ae..b50f78bc 100644
--- a/.golangci.toml
+++ b/.golangci.toml
@@ -40,6 +40,9 @@
     "Error return value of .((os\\.)?std(out|err)\\..*|.*Close|.*Flush|os\\.Remove(All)?|.*printf?|os\\.(Un)?Setenv). is not checked",
     "exported (type|method|function) (.+) should have comment or be unexported",
   ]
+  [[issues.exclude-rules]]
+    path = "(.+)_test.go"
+    linters = ["funlen"]
   [[issues.exclude-rules]]
     path = "providers/dns/dns_providers.go"
     linters = ["gocyclo"]
@@ -82,3 +85,18 @@
   [[issues.exclude-rules]]
     path = "providers/dns/sakuracloud/client_test.go"
     text = "cyclomatic complexity 13 of func `(TestDNSProvider_cleanupTXTRecord_concurrent|TestDNSProvider_addTXTRecord_concurrent)` is high"
+  [[issues.exclude-rules]]
+    path = "providers/dns/dns_providers.go"
+    text = "Function 'NewDNSChallengeProviderByName' has too many statements"
+  [[issues.exclude-rules]]
+    path = "cmd/flags.go"
+    text = "Function 'CreateFlags' is too long"
+  [[issues.exclude-rules]]
+    path = "certificate/certificates.go"
+    text = "Function 'GetOCSP' is too long"
+  [[issues.exclude-rules]]
+    path = "providers/dns/otc/client.go"
+    text = "Function 'loginRequest' is too long"
+  [[issues.exclude-rules]]
+    path = "providers/dns/gandi/gandi.go"
+    text = "Function 'Present' is too long"
diff --git a/.travis.yml b/.travis.yml
index 4cee2c00..3c005133 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,14 +1,29 @@
 language: go
 
-go:
-  - 1.12.x
-  - 1.x
+cache:
+  directories:
+    - $GOPATH/pkg/mod
+
+matrix:
+  fast_finish: true
+  include:
+    - go: 1.13.x
+      env: STABLE=true
+    - go: 1.x
+    - go: tip
+  allow_failures:
+    - go: tip
+
+go_import_path: github.com/go-acme/lego
+
+env:
+  global:
+    - MEMCACHED_HOSTS=localhost:11211
+    - GO111MODULE=on
 
 services:
   - memcached
 
-go_import_path: github.com/go-acme/lego
-
 addons:
   hosts:
   # for e2e tests
@@ -18,11 +33,6 @@ addons:
   - légô.wtf
   - xn--lg-bja9b.wtf
 
-env:
-  global:
-    - MEMCACHED_HOSTS=localhost:11211
-    - GO111MODULE=on
-
 before_install:
   - '[ "${TRAVIS_PULL_REQUEST}" = "false" ] && openssl aes-256-cbc -K $encrypted_26c593b079d9_key -iv $encrypted_26c593b079d9_iv -in .gitcookies.enc -out .gitcookies -d || true'
 
@@ -30,7 +40,7 @@ before_install:
   - GO111MODULE=off go get -u github.com/letsencrypt/pebble/...
 
   # Install linters and misspell
-  - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | bash -s -- -b $GOPATH/bin v1.17.1
+  - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | bash -s -- -b $GOPATH/bin ${GOLANGCI_LINT_VERSION}
   - golangci-lint --version
 
   # Hugo - documentation
@@ -38,7 +48,9 @@ before_install:
   - sudo dpkg -i /tmp/hugo.deb
 
 install:
-  - echo "TRAVIS_GO_VERSION=$TRAVIS_GO_VERSION"
+  - go mod tidy
+  - git diff --exit-code go.mod
+  - git diff --exit-code go.sum
   - go mod download
 
 before_script:
@@ -60,7 +72,7 @@ deploy:
     script: curl -sL https://git.io/goreleaser | bash
     on:
       tags: true
-      condition: $TRAVIS_GO_VERSION =~ ^1\.x$
+      condition: $STABLE = true
 
   - provider: releases
     api_key: ${GITHUB_TOKEN}
@@ -70,7 +82,7 @@ deploy:
     file_glob: true
     on:
       tags: true
-      condition: $TRAVIS_GO_VERSION =~ ^1\.x$
+      condition: $STABLE = true
 
   - provider: pages
     local_dir: docs/public
diff --git a/Dockerfile b/Dockerfile
index 8656df52..c73ed758 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM golang:1.12-alpine3.10 as builder
+FROM golang:1.13-alpine3.10 as builder
 
 RUN apk --no-cache --no-progress add make git
 
diff --git a/go.mod b/go.mod
index 517afca3..fb2da986 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/go-acme/lego/v3
 
-go 1.12
+go 1.13
 
 require (
 	github.com/Azure/azure-sdk-for-go v32.4.0+incompatible
@@ -26,7 +26,7 @@ require (
 	github.com/iij/doapi v0.0.0-20190504054126-0bbf12d6d7df
 	github.com/konsorten/go-windows-terminal-sequences v1.0.2 // indirect
 	github.com/labbsr0x/bindman-dns-webhook v1.0.0
-	github.com/labbsr0x/goh v0.0.0-20190417202808-8b16b4848295 // indirect
+	github.com/labbsr0x/goh v0.0.0-20190830205702-3d6988c73e10 // indirect
 	github.com/linode/linodego v0.10.0
 	github.com/liquidweb/liquidweb-go v1.6.0
 	github.com/miekg/dns v1.1.15
diff --git a/go.sum b/go.sum
index 3cb11fb6..7b9a36cc 100644
--- a/go.sum
+++ b/go.sum
@@ -150,8 +150,8 @@ github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/labbsr0x/bindman-dns-webhook v1.0.0 h1:gooRvyQtVOCtV/l9ZCI4CManZeVN/kUWG/vugRqHqv4=
 github.com/labbsr0x/bindman-dns-webhook v1.0.0/go.mod h1:pn4jcNjxSywRWDPDyGkFzgSnwty18OFdiUFc6S6fpgc=
-github.com/labbsr0x/goh v0.0.0-20190417202808-8b16b4848295 h1:5hXo89CXm3J5yyggBT3FJL4dN2gcfwxWwg0vXKiErSk=
-github.com/labbsr0x/goh v0.0.0-20190417202808-8b16b4848295/go.mod h1:RBxeaayaaMmp7GxwHiKANjkg9e+rxjOm4mB5vD5rt/I=
+github.com/labbsr0x/goh v0.0.0-20190830205702-3d6988c73e10 h1:mrPTy7qNJPGHaUkkN301r8Y+13l2/vsiC8Lvi09e6sI=
+github.com/labbsr0x/goh v0.0.0-20190830205702-3d6988c73e10/go.mod h1:RBxeaayaaMmp7GxwHiKANjkg9e+rxjOm4mB5vD5rt/I=
 github.com/linode/linodego v0.10.0 h1:AMdb82HVgY8o3mjBXJcUv9B+fnJjfDMn2rNRGbX+jvM=
 github.com/linode/linodego v0.10.0/go.mod h1:cziNP7pbvE3mXIPneHj0oRY8L1WtGEIKlZ8LANE4eXA=
 github.com/liquidweb/liquidweb-go v1.6.0 h1:vIj1I/Wf97fUnyirD+bi6Y63c0GiXk9nKI1+sFFl3G0=