vendor: Replace Sirupsen/logrus with sirupsen/logrus

With:

  $ git mv vendor/github.com/{S,s}irupsen
  $ sed -i 's/Sirupsen/sirupsen/g' $(git grep -l Sirupsen)

catching up with the upstream lowercasing [1,2,3,4].  Note the
compatibility issues discussed in [3], some consumers may prefer to
use the old uppercase version until they have time to update their
other Logrus consumers to the new lowercase form.

[1]: https://github.com/sirupsen/logrus/blame/v1.0.3/README.md#L6
[2]: sirupsen/logrus#384
[3]: sirupsen/logrus#570 (comment)
[4]: sirupsen/logrus#553

cmd/gomtree/main.go

@@ -10,7 +10,7 @@ import (
 	"os"
 	"strings"
 
-	"github.com/Sirupsen/logrus"
+	"github.com/sirupsen/logrus"
 	"github.com/vbatts/go-mtree"
 )
 

glide.yaml

@@ -6,7 +6,7 @@ import:
 - package: golang.org/x/crypto
   subpackages:
   - ripemd160
-- package: github.com/Sirupsen/logrus
+- package: github.com/sirupsen/logrus
   version: ^1.0.0
 - package: golang.org/x/sys
   version: 8dbc5d05d6edcc104950cc299a1ce6641235bc86

tar.go

@@ -9,7 +9,7 @@ import (
 	"path/filepath"
 	"strings"
 
-	"github.com/Sirupsen/logrus"
+	"github.com/sirupsen/logrus"
 	"github.com/vbatts/go-mtree/pkg/govis"
 )
 

update.go

@@ -5,7 +5,7 @@ import (
 	"os"
 	"sort"
 
-	"github.com/Sirupsen/logrus"
+	"github.com/sirupsen/logrus"
 )
 
 // DefaultUpdateKeywords is the default set of keywords that can take updates to the files on disk

update_test.go

@@ -13,7 +13,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/Sirupsen/logrus"
+	"github.com/sirupsen/logrus"
 )
 
 func init() {

updatefuncs.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/Sirupsen/logrus"
+	"github.com/sirupsen/logrus"
 	"github.com/vbatts/go-mtree/pkg/govis"
 )