Update gopsutil godep dependency. Dont use godep go build anymore

godep seems to have a problem when dependencies have `internal`
packages. So removing `godep go build` and `godep go test` from the
build process in favor of just checking out the correct revisions using
`godep restore` into the regular GOPATH.

This basically means that we are not actually using anything within the
Godeps directory except Godeps.json. I should probably make a separate
go dependency management system that does this.

internal/config/config.go

@@ -35,11 +35,11 @@ func NewConfig() *Config {
 	c := &Config{
 		// Agent defaults:
 		Agent: &AgentConfig{
-			Interval:      internal.Duration{10 * time.Second},
+			Interval:      internal.Duration{Duration: 10 * time.Second},
 			RoundInterval: true,
-			FlushInterval: internal.Duration{10 * time.Second},
+			FlushInterval: internal.Duration{Duration: 10 * time.Second},
 			FlushRetries:  2,
-			FlushJitter:   internal.Duration{5 * time.Second},
+			FlushJitter:   internal.Duration{Duration: 5 * time.Second},
 		},
 
 		Tags:          make(map[string]string),