Remove SavePatch and generate patches on the fly (#9302)

* Save patches to temporary files

* Remove SavePatch and generate patches on the fly

* Use ioutil.TempDir

* fixup! Use ioutil.TempDir

* fixup! fixup! Use ioutil.TempDir

* RemoveAll LocalCopyPath() in initIntergrationTest

* Default to status checking on PR creation

* Remove unnecessary set to StatusChecking

* Protect against unable to load repo

* Handle conflicts

* Restore original conflict setting

* In TestPullRequests update status to StatusChecking before running TestPatch

modules/git/repo_compare_test.go

@@ -5,6 +5,7 @@
 package git
 
 import (
+	"bytes"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -21,7 +22,8 @@ func TestGetFormatPatch(t *testing.T) {
 	repo, err := OpenRepository(clonedPath)
 	assert.NoError(t, err)
 	defer repo.Close()
-	rd, err := repo.GetFormatPatch("8d92fc95^", "8d92fc95")
+	rd := &bytes.Buffer{}
+	err = repo.GetPatch("8d92fc95^", "8d92fc95", rd)
 	assert.NoError(t, err)
 	patchb, err := ioutil.ReadAll(rd)
 	assert.NoError(t, err)