Switch to dep for dependency management

I find it to be a bit faster in some cases, and easier to work with.

.travis.yml

@@ -6,12 +6,9 @@ go:
 # blech, Travis downloads with capitals in DirectXMan12, which confuses go
 go_import_path: github.com/directxman12/k8s-prometheus-adapter
 
-addons:
-  apt:
-    sources:
-    - sourceline: 'ppa:masterminds/glide'
-    packages:
-    - glide
+before_install:
+- curl -L -s https://github.com/golang/dep/releases/download/v0.4.1/dep-linux-amd64 -o $GOPATH/bin/dep
+- chmod +x $GOPATH/bin/dep
 
 install:
 - make -B vendor
@@ -20,7 +17,7 @@ script: make verify
 
 cache:
   directories:
-  - ~/.glide
+  - ~/gopath/pkg/dep/
 
 sudo: required
 services: