reorganization of _examples and add some new examples such as iris+groupcache+mysql+docker

Former-commit-id: ed635ee95de7160cde11eaabc0c1dcb0e460a620

_examples/routing/basic/.dockerignore

@@ -0,0 +1,3 @@
+.git
+node_modules
+bin

_examples/routing/basic/Dockerfile

@@ -0,0 +1,17 @@
+# docker build -t myapp . 
+# docker run --rm -it -p 8080:8080 myapp:latest
+FROM golang:latest AS builder
+RUN apt-get update
+ENV GO111MODULE=on \
+    CGO_ENABLED=0 \
+    GOOS=linux \
+    GOARCH=amd64
+WORKDIR /go/src/app
+COPY go.mod .
+RUN go mod download
+COPY . .
+RUN go install
+
+FROM scratch
+COPY --from=builder /go/bin/app .
+ENTRYPOINT ["./app"]

_examples/routing/basic/README.md

@@ -0,0 +1,27 @@
+# Basic Example
+
+The only requirement for this example is [Docker](https://docs.docker.com/install/).
+
+## Docker Compose
+
+The Docker Compose is pre-installed with Docker for Windows. For linux please follow the steps described at: https://docs.docker.com/compose/install/.
+
+Build and run the application for linux arch and expose it on http://localhost:8080.
+
+```sh
+$ docker-compose up
+```
+
+See [docker-compose file](docker-compose.yml).
+
+## Without Docker Compose
+
+1. Build the image as "myapp" (docker build)
+2. Run the image and map exposed ports (-p 8080:8080)
+3. Attach the interactive mode so CTRL/CMD+C signals are respected to shutdown the Iris Server (-it)
+4. Cleanup the image on finish (--rm)
+
+```sh
+$ docker build -t myapp . 
+$ docker run --rm -it -p 8080:8080 myapp:latest
+```

_examples/routing/basic/docker-compose.yml

@@ -0,0 +1,8 @@
+# docker-compose up [--build]
+version: '3'
+
+services:
+  app:
+    build: .
+    ports:
+      - 8080:8080

_examples/routing/basic/main.go

@@ -133,7 +133,7 @@ func newApp() *iris.Application {
 	{ // braces are optional, it's just type of style, to group the routes visually.
 
 		// http://v1.localhost:8080
-		// Note: for versioning-specific features checkout the _examples/versioning instead.
+		// Note: for versioning-specific features checkout the _examples/routing/versioning instead.
 		v1.Get("/", func(ctx iris.Context) {
 			ctx.HTML(`Version 1 API. go to <a href="/api/users">/api/users</a>`)
 		})

_examples/routing/basic/main_test.go

@@ -11,7 +11,7 @@ import (
 // The tests are written in a way to be easy to understand,
 // for a more comprehensive testing examples check out the:
 // _examples/routing/main_test.go,
-// _examples/subdomains/www/main_test.go
+// _examples/routing/subdomains/www/main_test.go
 // _examples/file-server and e.t.c.
 // Almost every example which covers
 // a new feature from you to learn