Do not put migrations under their own root

Since the migrations are not displayed on the dirtributions, there is not need to organize them under their own root to reduce visual clutter.  Having each migration follow the same path as all other distributions makes each easier to find in the absence of a link displayed on the distributions web page.  It also avoids complicating the distribution deployment scripts and allows each migration distribution to be treated the same as any other distribution.

repo/fsrepo/migrations/migrations.go

@@ -14,8 +14,8 @@ import (
 )
 
 const (
-	// Migrations distribution
-	distMigsRoot = "go-ipfs-repo-migrations"
+	// Migrations subdirectory in distribution. Empty for root (no subdir).
+	distMigsRoot = ""
 	distFSRM     = "fs-repo-migrations"
 )
 

repo/fsrepo/migrations/migrations_test.go

@@ -3,8 +3,10 @@ package migrations
 import (
 	"context"
 	"io/ioutil"
+	"net/http"
 	"os"
 	"path"
+	"strings"
 	"testing"
 )
 
@@ -57,17 +59,23 @@ func TestFindMigrations(t *testing.T) {
 }
 
 func TestFetchMigrations(t *testing.T) {
-	t.Skip("skip - migrations not available on distribution site yet")
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	_, err := LatestDistVersion(ctx, "ipfs-1-to-2")
+	if err != nil {
+		if strings.Contains(err.Error(), http.StatusText(http.StatusNotFound)) {
+			t.Skip("skip - migrations not yet available on distribution site")
+		}
+		t.Fatal(err)
+	}
 
 	tmpDir, err := ioutil.TempDir("", "migratetest")
 	if err != nil {
 		panic(err)
 	}
 	defer os.RemoveAll(tmpDir)
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
 	needed := []string{"ipfs-1-to-2", "ipfs-2-to-3"}
 	fetched, err := fetchMigrations(ctx, needed, tmpDir)
 	if err != nil {