Revert "update CI and everything to Go 1.14."

This reverts commit 905fe9f6a2.

We're not quite ready to update the Mac/iOS builds to 1.14.

.github/workflows/cross-darwin.yml

@@ -16,10 +16,10 @@ jobs:
 
     steps:
 
-    - name: Set up Go 1.14
+    - name: Set up Go 1.13
       uses: actions/setup-go@v1
       with:
-        go-version: 1.14
+        go-version: 1.13
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/cross-freebsd.yml

@@ -16,10 +16,10 @@ jobs:
 
     steps:
 
-    - name: Set up Go 1.14
+    - name: Set up Go 1.13
       uses: actions/setup-go@v1
       with:
-        go-version: 1.14
+        go-version: 1.13
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/cross-openbsd.yml

@@ -16,10 +16,10 @@ jobs:
 
     steps:
 
-    - name: Set up Go 1.14
+    - name: Set up Go 1.13
       uses: actions/setup-go@v1
       with:
-        go-version: 1.14
+        go-version: 1.13
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/cross-windows.yml

@@ -16,10 +16,10 @@ jobs:
 
     steps:
 
-    - name: Set up Go 1.14
+    - name: Set up Go 1.13
       uses: actions/setup-go@v1
       with:
-        go-version: 1.14
+        go-version: 1.13
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/linux.yml

@@ -16,10 +16,10 @@ jobs:
 
     steps:
 
-    - name: Set up Go 1.14
+    - name: Set up Go 1.13
       uses: actions/setup-go@v1
       with:
-        go-version: 1.14
+        go-version: 1.13
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/staticcheck.yml

@@ -13,10 +13,10 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - name: Set up Go 1.14
+    - name: Set up Go 1.13
       uses: actions/setup-go@v1
       with:
-        go-version: 1.14
+        go-version: 1.13
 
     - name: Check out code
       uses: actions/checkout@v1

Dockerfile

@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
-FROM golang:1.14-alpine AS build-env
+FROM golang:1.13-alpine AS build-env
 
 WORKDIR /go/src/tailscale
 

README.md

@@ -24,7 +24,7 @@ go install tailscale.com/cmd/tailscale{,d}
 ```
 
 We only support the latest Go release and any Go beta or release
-candidate builds (currently Go 1.14 or Go 1.15) in module mode. It
+candidate builds (currently Go 1.13.x or Go 1.14) in module mode. It
 might work in earlier Go versions or in GOPATH mode, but we're making
 no effort to keep those working.
 

go.mod

@@ -1,6 +1,6 @@
 module tailscale.com
 
-go 1.14
+go 1.13
 
 require (
 	github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239 // indirect