Change from notification after_success and after_failure to change

Also removes the extra db field; instead, just send Prior as part of the Request.

This reverts commit e8b993e7da.

shared/model/commit.go

@@ -8,7 +8,6 @@ type Commit struct {
 	ID          int64  `meddler:"commit_id,pk"     json:"id"`
 	RepoID      int64  `meddler:"repo_id"          json:"-"`
 	Status      string `meddler:"commit_status"    json:"status"`
-	PriorStatus string `meddler:"commit_prior_status" json:"prior_status"`
 	Started     int64  `meddler:"commit_started"   json:"started_at"`
 	Finished    int64  `meddler:"commit_finished"  json:"finished_at"`
 	Duration    int64  `meddler:"commit_duration"  json:"duration"`

shared/model/request.go

@@ -5,4 +5,5 @@ type Request struct {
 	User   *User   `json:"-"`
 	Repo   *Repo   `json:"repo"`
 	Commit *Commit `json:"commit"`
+	Prior  *Commit `json:"prior_commit"`
 }