Actually shorten the commit SHA

src/github.com/matrix-org/go-neb/services/travisci/travisci.go

@@ -118,8 +118,12 @@ func notifToTemplate(n webhookNotification) map[string]string {
 	t["build_number"] = n.Number
 	t["build_id"] = strconv.Itoa(n.ID)
 	t["branch"] = n.Branch
-	t["commit"] = n.Commit
-	t["author"] = n.CommitterName // author: commit author name
+	shaLength := len(n.Commit)
+	if shaLength > 10 {
+		shaLength = 10
+	}
+	t["commit"] = n.Commit[:shaLength] // shortened commit SHA
+	t["author"] = n.CommitterName      // author: commit author name
 	// commit_message: commit message of build
 	// commit_subject: first line of the commit message
 	t["commit_message"] = n.Message

src/github.com/matrix-org/go-neb/services/travisci/travisci_test.go

@@ -71,18 +71,18 @@ var travisTests = []struct {
 	{
 		exampleSignature, true, exampleBody,
 		"%{repository}#%{build_number} (%{branch} - %{commit} : %{author}): %{message}",
-		"Kegsay/flow-jsdoc#18 (master - 3a092c3a6032ebb50384c99b445f947e9ce86e2a : Kegan Dougal): Passed",
+		"Kegsay/flow-jsdoc#18 (master - 3a092c3a60 : Kegan Dougal): Passed",
 	},
 	{
 		"obviously_invalid_signature", false, exampleBody,
 		"%{repository}#%{build_number} (%{branch} - %{commit} : %{author}): %{message}",
-		"Kegsay/flow-jsdoc#18 (master - 3a092c3a6032ebb50384c99b445f947e9ce86e2a : Kegan Dougal): Passed",
+		"Kegsay/flow-jsdoc#18 (master - 3a092c3a60 : Kegan Dougal): Passed",
 	},
 	{
 		// Payload is valid but doesn't match signature now
 		exampleSignature, false, strings.TrimSuffix(exampleBody, "%7D") + "%2C%22EXTRA_KEY%22%3Anull%7D",
 		"%{repository}#%{build_number} (%{branch} - %{commit} : %{author}): %{message}",
-		"Kegsay/flow-jsdoc#18 (master - 3a092c3a6032ebb50384c99b445f947e9ce86e2a : Kegan Dougal): Passed",
+		"Kegsay/flow-jsdoc#18 (master - 3a092c3a60 : Kegan Dougal): Passed",
 	},
 	{
 		exampleSignature, true, exampleBody,