Pack the models.Commit struct a little tighter

Change the base type of some of our enums from int to uint8, and reorder fields
for better packing. This reduces the size of models.Commit from 152 to 132 bytes
on my machine.

This doesn't improve overall memory usage significantly, but why not save a
little bit of memory if it's easy.

pkg/commands/models/commit.go

@@ -11,7 +11,7 @@ import (
 // Special commit hash for empty tree object
 const EmptyTreeCommitHash = "4b825dc642cb6eb9a060e54bf8d69288fbee4904"
 
-type CommitStatus int
+type CommitStatus uint8
 
 const (
 	StatusNone CommitStatus = iota
@@ -30,7 +30,7 @@ const (
 	ActionNone todo.TodoCommand = 0
 )
 
-type Divergence int
+type Divergence uint8
 
 // For a divergence log (left/right comparison of two refs) this is set to
 // either DivergenceLeft or DivergenceRight for each commit; for normal
@@ -45,17 +45,18 @@ const (
 type Commit struct {
 	hash          *string
 	Name          string
-	Status        CommitStatus
-	Action        todo.TodoCommand
 	Tags          []string
 	ExtraInfo     string // something like 'HEAD -> master, tag: v0.15.2'
 	AuthorName    string // something like 'Jesse Duffield'
 	AuthorEmail   string // something like 'jessedduffield@gmail.com'
 	UnixTimestamp int64
-	Divergence    Divergence // set to DivergenceNone unless we are showing the divergence view
 
 	// Hashes of parent commits (will be multiple if it's a merge commit)
 	parents []*string
+
+	Status     CommitStatus
+	Action     todo.TodoCommand
+	Divergence Divergence // set to DivergenceNone unless we are showing the divergence view
 }
 
 type NewCommitOpts struct {