add linux target to Makefile

Author: pb82

Makefile

@@ -2,6 +2,9 @@
 build:
 	go build -o mobile ./cmd/mobile
 
+build_linux:
+	env GOOS=linux GOARCH=amd64 go build -o mobile ./cmd/mobile
+
 generate:
 	vendor/k8s.io/code-generator/generate-internal-groups.sh client github.com/aerogear/mobile-cli/pkg/client/mobile github.com/aerogear/mobile-cli/pkg/apis github.com/aerogear/mobile-cli/pkg/apis  "mobile:v1alpha1"
 	vendor/k8s.io/code-generator/generate-internal-groups.sh client github.com/aerogear/mobile-cli/pkg/client/servicecatalog github.com/aerogear/mobile-cli/pkg/apis github.com/aerogear/mobile-cli/pkg/apis  "servicecatalog:v1beta1"

Readme.md

@@ -36,7 +36,7 @@ git clone https://github.com/aerogear/mobile-cli
 
 ```
 glide install
-make
+make build
 ```
 To test run
 
@@ -49,7 +49,7 @@ To test run
 To use the mobile-cli inside an APB container it needs to be compiled for the linux/amd64 platform:
 
 ```
-env GOOS=linux GOARCH=amd64 go build -o mobile ./cmd/mobile
+make build_linux
 ```
 
 ### Install