Fix type for commit.duration in BuildEvent (#361)

* Fix the PipelineEvent struct, with proper sub struct for Runner and correct type for the artifacts_file 'size' field

* Updated tests for changes to PipelineEvent

* Formatting

* Naming

* BuildEvent BuildDuration is a float, not a string

* float64

* Duration is an integer, not a string

event_types.go

@@ -641,7 +641,7 @@ type BuildEvent struct {
 		AuthorName  string `json:"author_name"`
 		AuthorEmail string `json:"author_email"`
 		Status      string `json:"status"`
-		Duration    string `json:"duration"`
+		Duration    int    `json:"duration"`
 		StartedAt   string `json:"started_at"`
 		FinishedAt  string `json:"finished_at"`
 	} `json:"commit"`

event_types_test.go

@@ -440,7 +440,7 @@ func TestBuildEventUnmarshal(t *testing.T) {
     "author_name": "User",
     "author_email": "user@gitlab.com",
     "status": "created",
-    "duration": null,
+    "duration": 199,
     "started_at": null,
     "finished_at": null
   },