Adjustment from the tests.

Author: rickypc

host.go

@@ -62,9 +62,7 @@
 //   ...
 //
 //   // When you need to uninstall.
-//   if err := host.Uninstall(); err != nil {
-//     log.Printf("uninstall error: %v", err)
-//   }
+//   host.Uninstall()
 //
 // * Auto Update Configuration
 //
@@ -98,13 +96,23 @@ import (
 	"encoding/binary"
 	"encoding/json"
 	"io"
+	"io/ioutil"
 	"os"
 	"path"
 	"path/filepath"
 	"runtime"
 	"strings"
 )
 
+// ioutilWriteFile is a shortcut to ioutil.WriteFile. It helps write testable code.
+var ioutilWriteFile = ioutil.WriteFile
+
+// osMkdirAll is a shortcut to os.MkdirAll. It helps write testable code.
+var osMkdirAll = os.MkdirAll
+
+// runtimeGoexit is a shortcut to runtime.Goexit. It helps write testable code.
+var runtimeGoexit = runtime.Goexit
+
 // H is a map[string]interface{} type shortcut and represents a dynamic
 // key-value-pair data.
 type H map[string]interface{}
@@ -123,9 +131,6 @@ type Host struct {
 	Version     string           `json:"-"`
 }
 
-// runtimeGoexit is a shortcut to runtime.Goexit. It helps write testable code.
-var runtimeGoexit = runtime.Goexit
-
 // Init sets default value to its fields and return the Host pointer back.
 //
 // * AppName is an application name in manifest file and will be defaulted to