Merge branch 'master' into redundant-nil-check-slice

.travis.yml

@@ -2,7 +2,7 @@ language: go
 sudo: false
 dist: trusty
 osx_image: xcode8.3
-go: 1.8.x
+go: 1.11.x
 
 os:
 - linux

app.go

@@ -495,11 +495,12 @@ func (a Author) String() string {
 // it's an ActionFunc or a func with the legacy signature for Action, the func
 // is run!
 func HandleAction(action interface{}, context *Context) (err error) {
-	if a, ok := action.(ActionFunc); ok {
+	switch a := action.(type) {
+	case ActionFunc:
 		return a(context)
-	} else if a, ok := action.(func(*Context) error); ok {
+	case func(*Context) error:
 		return a(context)
-	} else if a, ok := action.(func(*Context)); ok { // deprecated function signature
+	case func(*Context): // deprecated function signature
 		a(context)
 		return nil
 	}

command.go

@@ -57,7 +57,7 @@ type Command struct {
 	// Boolean to hide this command from help or completion
 	Hidden bool
 	// Boolean to enable short-option handling so user can combine several
-	// single-character bool arguements into one
+	// single-character bool arguments into one
 	// i.e. foobar -o -v -> foobar -ov
 	UseShortOptionHandling bool