Support Go 1.16 and drop support for Go 1.15

- Document CLI install instructions for Go 1.16
- Update golangci-lint from v1.33.0 to v1.37.0

.circleci/config.yml

@@ -4,7 +4,7 @@
 version: 2.1
 
 jobs:
-  "golang-1_14": &template
+  "golang-1_15": &template
     machine:
       # https://circleci.com/docs/2.0/configuration-reference/#available-machine-images
       image: ubuntu-2004:202010-01
@@ -19,7 +19,7 @@ jobs:
 
     environment:
       GO111MODULE: "on"
-      GO_VERSION: "1.14.x"
+      GO_VERSION: "1.15.x"
 
     steps:
       # - setup_remote_docker:
@@ -29,7 +29,7 @@ jobs:
       - run: curl -sfL -o ~/bin/golangci-lint.sh https://install.goreleaser.com/github.com/golangci/golangci-lint.sh
       - run: chmod +x ~/bin/gimme ~/bin/golangci-lint.sh
       - run: eval "$(gimme $GO_VERSION)"
-      - run: golangci-lint.sh -b ~/bin v1.33.0
+      - run: golangci-lint.sh -b ~/bin v1.37.0
       - checkout
       - restore_cache:
           keys:
@@ -43,14 +43,14 @@ jobs:
       - run: go get github.com/mattn/goveralls
       - run: goveralls -service=circle-ci -coverprofile /tmp/coverage/combined.txt
 
-  "golang-1_15":
+  "golang-1_16":
     <<: *template
     environment:
-      GO_VERSION: "1.15.x"
+      GO_VERSION: "1.16.x"
 
 workflows:
   version: 2
   build:
     jobs:
-      - "golang-1_14"
       - "golang-1_15"
+      - "golang-1_16"

README.md

@@ -3,7 +3,7 @@
 [![Coverage Status](https://img.shields.io/coveralls/github/golang-migrate/migrate/master.svg)](https://coveralls.io/github/golang-migrate/migrate?branch=master)
 [![packagecloud.io](https://img.shields.io/badge/deb-packagecloud.io-844fec.svg)](https://packagecloud.io/golang-migrate/migrate?filter=debs)
 [![Docker Pulls](https://img.shields.io/docker/pulls/migrate/migrate.svg)](https://hub.docker.com/r/migrate/migrate/)
-![Supported Go Versions](https://img.shields.io/badge/Go-1.14%2C%201.15-lightgrey.svg)
+![Supported Go Versions](https://img.shields.io/badge/Go-1.15%2C%201.16-lightgrey.svg)
 [![GitHub Release](https://img.shields.io/github/release/golang-migrate/migrate.svg)](https://github.com/golang-migrate/migrate/releases)
 [![Go Report Card](https://goreportcard.com/badge/github.com/golang-migrate/migrate)](https://goreportcard.com/report/github.com/golang-migrate/migrate)
 

cmd/migrate/README.md

@@ -41,17 +41,21 @@ $ apt-get install -y migrate
 $ go get -u -d github.com/golang-migrate/migrate/cmd/migrate
 $ cd $GOPATH/src/github.com/golang-migrate/migrate/cmd/migrate
 $ git checkout $TAG  # e.g. v4.1.0
+$ # Go 1.15 and below
 $ go build -tags 'postgres' -ldflags="-X main.Version=$(git describe --tags)" -o $GOPATH/bin/migrate $GOPATH/src/github.com/golang-migrate/migrate/cmd/migrate
+$ # Go 1.16+
+$ go install -tags 'postgres' -o $GOPATH/bin/migrate github.com/golang-migrate/migrate/v4/cmd/migrate@$TAG
 ```
 
 #### Unversioned
 
 ```bash
+$ # Go 1.15 and below
 $ go get -tags 'postgres' -u github.com/golang-migrate/migrate/cmd/migrate
+$ # Go 1.16+
+$ go install -tags 'postgres' github.com/golang-migrate/migrate/v4/cmd/migrate@latest
 ```
 
-[Make sure](https://github.com/golang-migrate/migrate/pull/257#issuecomment-705249902) you're not installing the `migrate` CLI from a module. e.g. there should not be any `go.mod` files in your current directory or any directory from your current one to the root
-
 #### Notes
 
 1. Requires a version of Go that [supports modules](https://golang.org/cmd/go/#hdr-Preliminary_module_support). e.g. Go 1.11+
@@ -62,6 +66,7 @@ correspond to the names of the sub-packages underneath the
 [`database`](../database) package.
 1. Similarly to the database build tags, if you need to support other sources, use the appropriate build tag(s).
 1. Support for build constraints will be removed in the future: https://github.com/golang-migrate/migrate/issues/60
+1. For versions of Go 1.15 and lower, [make sure](https://github.com/golang-migrate/migrate/pull/257#issuecomment-705249902) you're not installing the `migrate` CLI from a module. e.g. there should not be any `go.mod` files in your current directory or any directory from your current directory to the root
 
 ## Usage