Add new examples to kompose (#1803)

#### What type of PR is this?

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Add one of the following kinds:
/kind bug
/kind documentation
/kind feature
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/kind cleanup

#### What this PR does / why we need it:

Fixes the current broken examples by:

* Removing all the old incompatible ones (we do not really support v3
  anymore or v2... since switching libraries)
* Uses quay.io/kompose/web as our front end example which is a fork of
  the guestbook-go kubernetes examples

#### Which issue(s) this PR fixes:
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*Automatically closes linked issue when PR is merged.
Usage: `Fixes #<issue number>`, or `Fixes (paste link of issue)`.
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Closes https://github.com/kubernetes/kompose/issues/1757

#### Special notes for your reviewer:

Test using docker-compose (you'll see it come up!), then try with
kompose :)

Signed-off-by: Charlie Drage <charlie@charliedrage.com>

examples/web/vendor/github.com/codegangsta/negroni/doc.go

@@ -0,0 +1,25 @@
+// Package negroni is an idiomatic approach to web middleware in Go. It is tiny, non-intrusive, and encourages use of net/http Handlers.
+//
+// If you like the idea of Martini, but you think it contains too much magic, then Negroni is a great fit.
+//
+// For a full guide visit http://github.com/urfave/negroni
+//
+//	package main
+//
+//	import (
+//	  "github.com/urfave/negroni"
+//	  "net/http"
+//	  "fmt"
+//	)
+//
+//	func main() {
+//	  mux := http.NewServeMux()
+//	  mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
+//	    fmt.Fprintf(w, "Welcome to the home page!")
+//	  })
+//
+//	  n := negroni.Classic()
+//	  n.UseHandler(mux)
+//	  n.Run(":3000")
+//	}
+package negroni