Add notes about dep.

Author: AlekSi

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## v0.4.0 (not released yet)
+
+* Go vendoring switched to [dep](https://github.com/golang/dep).
+
 ## v0.3.1 (2017-09-08)
 
 * Better logging for scrape errors.

CONTRIBUTING.md

@@ -16,5 +16,5 @@ export MONGODB_URL='mongodb://localhost:27017'
 
 ## Vendoring
 
-We use [Glide](https://glide.sh) to vendor dependencies. Please use released version of Glide (i.e. do not `go get`
-from `master` branch). Also please use `--strip-vendor` flag.
+We use [dep](https://github.com/golang/dep) to vendor dependencies.
+Please use released version of dep (i.e. do not `go get` from `master` branch).