mozzle: Use windows equivalent to linux's $HOME when on windows

Otherwise the CF CLI config.json file will not be found:
  mozzle: error reading CF CLI config: error open ".cf\config.json": open .cf\config.json: The system cannot find the path specified.

Fixes #16.

cmd/mozzle/homedir.go

@@ -0,0 +1,18 @@
+// +build !windows
+
+package main
+
+import (
+	"os"
+)
+
+func homeDir() string {
+	var homeDir string
+	switch {
+	case os.Getenv("CF_HOME") != "":
+		homeDir = os.Getenv("CF_HOME")
+	default:
+		homeDir = os.Getenv("HOME")
+	}
+	return homeDir
+}

cmd/mozzle/homedir_windows.go

@@ -0,0 +1,22 @@
+// +build windows
+
+package main
+
+import (
+	"os"
+)
+
+func homeDir() string {
+	var homeDir string
+	switch {
+	case os.Getenv("CF_HOME") != "":
+		homeDir = os.Getenv("CF_HOME")
+	case os.Getenv("HOMEDRIVE")+os.Getenv("HOMEPATH") != "":
+		homeDir = os.Getenv("HOMEDRIVE") + os.Getenv("HOMEPATH")
+	default:
+		homeDir = os.Getenv("USERPROFILE")
+	}
+
+	return homeDir
+
+}

cmd/mozzle/main.go

@@ -163,11 +163,7 @@ type cliConfig struct {
 // The default location is CF_HOME/.cf/config.json.
 // If the CF_HOME env variable is not set, it defaults to HOME env variable.
 func cfcliConfig() (*cliConfig, error) {
-	var path string
-	if path = os.Getenv("CF_HOME"); path == "" {
-		path = os.Getenv("HOME")
-	}
-	path = filepath.Join(path, ".cf/config.json")
+	path := filepath.Join(homeDir(), ".cf", "config.json")
 	fd, err := os.Open(path)
 	if err != nil {
 		return nil, errors.Wrapf(err, "error open %q", path)