Don't setup suite if no methods satisfy filter

When suite setup is long, the necessity to wait for all suite setups for testing one single method bothers a lot. Here's a little fix of that behavior.

suite/suite.go

@@ -82,14 +82,7 @@ func Run(t *testing.T, suite TestingSuite) {
 	suite.SetT(t)
 	defer failOnPanic(t)
 
-	if setupAllSuite, ok := suite.(SetupAllSuite); ok {
+	setupDone := false
-		setupAllSuite.SetupSuite()
-	}
-	defer func() {
-		if tearDownAllSuite, ok := suite.(TearDownAllSuite); ok {
-			tearDownAllSuite.TearDownSuite()
-		}
-	}()
 	
 	methodFinder := reflect.TypeOf(suite)
 	tests := []testing.InternalTest{}
@@ -100,7 +93,20 @@ func Run(t *testing.T, suite TestingSuite) {
 			fmt.Fprintf(os.Stderr, "testify: invalid regexp for -m: %s\n", err)
 			os.Exit(1)
 		}
-		if ok {
+		if !ok {
+			continue
+		}
+		if !setupDone {
+			if setupAllSuite, ok := suite.(SetupAllSuite); ok {
+				setupAllSuite.SetupSuite()
+			}
+			defer func() {
+				if tearDownAllSuite, ok := suite.(TearDownAllSuite); ok {
+					tearDownAllSuite.TearDownSuite()
+				}
+			}()
+			setupDone = true
+		}
 		test := testing.InternalTest{
 			Name: method.Name,
 			F: func(t *testing.T) {
@@ -128,7 +134,6 @@ func Run(t *testing.T, suite TestingSuite) {
 		}
 		tests = append(tests, test)
 	}
-	}
 	runTests(t, tests)
 }