[Vendor] update go-swagger v0.21.0 -> v0.25.0 (#12670)

* Update go-swagger

* vendor

vendor/github.com/subosito/gotenv/README.md

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+# gotenv
+
+[![Build Status](https://travis-ci.org/subosito/gotenv.svg?branch=master)](https://travis-ci.org/subosito/gotenv)
+[![Build status](https://ci.appveyor.com/api/projects/status/wb2e075xkfl0m0v2/branch/master?svg=true)](https://ci.appveyor.com/project/subosito/gotenv/branch/master)
+[![Coverage Status](https://badgen.net/codecov/c/github/subosito/gotenv)](https://codecov.io/gh/subosito/gotenv)
+[![Go Report Card](https://goreportcard.com/badge/github.com/subosito/gotenv)](https://goreportcard.com/report/github.com/subosito/gotenv)
+[![GoDoc](https://godoc.org/github.com/subosito/gotenv?status.svg)](https://godoc.org/github.com/subosito/gotenv)
+
+Load environment variables dynamically in Go.
+
+## Usage
+
+Put the gotenv package on your `import` statement:
+
+```go
+import "github.com/subosito/gotenv"
+```
+
+To modify your app environment variables, `gotenv` expose 2 main functions:
+
+- `gotenv.Load`
+- `gotenv.Apply`
+
+By default, `gotenv.Load` will look for a file called `.env` in the current working directory.
+
+Behind the scene, it will then load `.env` file and export the valid variables to the environment variables. Make sure you call the method as soon as possible to ensure it loads all variables, say, put it on `init()` function.
+
+Once loaded you can use `os.Getenv()` to get the value of the variable.
+
+Let's say you have `.env` file:
+
+```
+APP_ID=1234567
+APP_SECRET=abcdef
+```
+
+Here's the example of your app:
+
+```go
+package main
+
+import (
+	"github.com/subosito/gotenv"
+	"log"
+	"os"
+)
+
+func init() {
+	gotenv.Load()
+}
+
+func main() {
+	log.Println(os.Getenv("APP_ID"))     // "1234567"
+	log.Println(os.Getenv("APP_SECRET")) // "abcdef"
+}
+```
+
+You can also load other than `.env` file if you wish. Just supply filenames when calling `Load()`. It will load them in order and the first value set for a variable will win.:
+
+```go
+gotenv.Load(".env.production", "credentials")
+```
+
+While `gotenv.Load` loads entries from `.env` file, `gotenv.Apply` allows you to use any `io.Reader`:
+
+```go
+gotenv.Apply(strings.NewReader("APP_ID=1234567"))
+
+log.Println(os.Getenv("APP_ID"))
+// Output: "1234567"
+```
+
+Both `gotenv.Load` and `gotenv.Apply` **DO NOT** overrides existing environment variables. If you want to override existing ones, you can see section below.
+
+### Environment Overrides
+
+Besides above functions, `gotenv` also provides another functions that overrides existing:
+
+- `gotenv.OverLoad`
+- `gotenv.OverApply`
+
+
+Here's the example of this overrides behavior:
+
+```go
+os.Setenv("HELLO", "world")
+
+// NOTE: using Apply existing value will be reserved
+gotenv.Apply(strings.NewReader("HELLO=universe"))
+fmt.Println(os.Getenv("HELLO"))
+// Output: "world"
+
+// NOTE: using OverApply existing value will be overridden
+gotenv.OverApply(strings.NewReader("HELLO=universe"))
+fmt.Println(os.Getenv("HELLO"))
+// Output: "universe"
+```
+
+### Throw a Panic
+
+Both `gotenv.Load` and `gotenv.OverLoad` returns an error on something wrong occurred, like your env file is not exist, and so on. To make it easier to use, `gotenv` also provides `gotenv.Must` helper, to let it panic when an error returned.
+
+```go
+err := gotenv.Load(".env-is-not-exist")
+fmt.Println("error", err)
+// error: open .env-is-not-exist: no such file or directory
+
+gotenv.Must(gotenv.Load, ".env-is-not-exist")
+// it will throw a panic
+// panic: open .env-is-not-exist: no such file or directory
+```
+
+### Another Scenario
+
+Just in case you want to parse environment variables from any `io.Reader`, gotenv keeps its `Parse` and `StrictParse` function as public API so you can use that.
+
+```go
+// import "strings"
+
+pairs := gotenv.Parse(strings.NewReader("FOO=test\nBAR=$FOO"))
+// gotenv.Env{"FOO": "test", "BAR": "test"}
+
+err, pairs = gotenv.StrictParse(strings.NewReader(`FOO="bar"`))
+// gotenv.Env{"FOO": "bar"}
+```
+
+`Parse` ignores invalid lines and returns `Env` of valid environment variables, while `StrictParse` returns an error for invalid lines.
+
+## Notes
+
+The gotenv package is a Go port of [`dotenv`](https://github.com/bkeepers/dotenv) project with some additions made for Go. For general features, it aims to be compatible as close as possible.