Using dep in travis to ensure all dependencies are installed (kubernetes-sigs#471)

* Using dep in travis to ensure all dependencies are installed

* Using dep in travis to ensure all dependencies are installed

* Using dep in travis to ensure all dependencies are installed

* Using dep in travis to ensure all dependencies are installed

Author: njuettner

.gitignore

@@ -43,3 +43,6 @@ cscope.*
 cover.out
 *.coverprofile
 external-dns
+
+# vendor dir
+vendor/

.travis.yml

@@ -14,6 +14,8 @@ matrix:
   - go: tip
 
 before_install:
+- go get -u github.com/golang/dep/cmd/dep
+- dep ensure -vendor-only
 - go get github.com/mattn/goveralls
 - go get github.com/alecthomas/gometalinter
 

README.md

@@ -66,10 +66,16 @@ Make sure you have the following prerequisites:
 
 First, get ExternalDNS:
 
+**To install all dependencies, make sure to install [dep](https://github.com/golang/dep) first.**
+
 ```console
-$ go get -u github.com/kubernetes-incubator/external-dns
+$ git clone https://github.com/kubernetes-incubator/external-dns.git && cd external-dns
+$ dep ensure -vendor-only
+$ make
 ```
 
+This will create external-dns in the build directory directly from master.
+
 Next, run an application and expose it via a Kubernetes Service:
 
 ```console