lib/util: Update UUID vendor

It appears github.com/satori/go.uuid is functionally deprecated,
and has been superceded by github.com/gofrs/uuid.

- satori/go.uuid#84
- satori/go.uuid#90

This came to my attention because of un-tagged changes to
satori/go.uuid that changed the signature of uuid.NewV4()
from a single return val to two, resulting in:

$ go get github.com/Jeffail/leaps/cmd/...
warning: ignoring symlink /Users/ia/go/src/github.com/Jeffail/leaps/cmd/leaps/www
warning: ignoring symlink /Users/ia/go/src/github.com/Jeffail/leaps/cmd/leaps/www
# github.com/Jeffail/leaps/lib/util
go/src/github.com/Jeffail/leaps/lib/util/uuid_gen.go:51:19: multiple-value uuid.NewV4() in single-value context

Of course running 'dep ensure' fixed this issue, but
it seems like this project should use the 'longer fork'
of this dependency in any case.

This change does NOT address the 'what to do with the
error value' question; it just ignores the possible error.

Gopkg.toml

@@ -66,8 +66,8 @@
   name = "github.com/lib/pq"
 
 [[constraint]]
-  name = "github.com/satori/go.uuid"
-  version = "1.2.0"
+  name = "github.com/gofrs/uuid"
+  version = "3.1.2"
 
 [[constraint]]
   name = "gopkg.in/alexcesaro/statsd.v2"

lib/util/uuid_gen.go

@@ -29,7 +29,7 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/satori/go.uuid"
+	"github.com/gofrs/uuid"
 )
 
 /*--------------------------------------------------------------------------------------------------
@@ -48,7 +48,8 @@ func GenerateStampedUUID() string {
 GenerateUUID - Generates a UUID and returns it as a hex encoded string.
 */
 func GenerateUUID() string {
-	return uuid.NewV4().String()
+	u, _ := uuid.NewV4()
+	return u.String()
 }
 
 /*--------------------------------------------------------------------------------------------------