First time mode for controller

- Upon first time invocation ``minio controller`` would create access keys and secret id
- Upon request passing 'keys' arg ``minio controller`` would provide the keys
- Add colorized notification

notifier.go

@@ -0,0 +1,72 @@
+/*
+ * Minio Cloud Storage, (C) 2015 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package main
+
+import (
+	"fmt"
+	"runtime"
+	"strings"
+
+	"github.com/fatih/color"
+	"github.com/olekukonko/ts"
+)
+
+// colorizeMessage - inspired from Yeoman project npm package https://github.com/yeoman/update-notifier
+func colorizeMessage(message string) string {
+	// initialize coloring
+	cyan := color.New(color.FgCyan, color.Bold).SprintFunc()
+	yellow := color.New(color.FgYellow, color.Bold).SprintfFunc()
+
+	// calculate length without color coding, due to ANSI color characters padded to actual
+	// string the final length is wrong than the original string length
+	lineStr := fmt.Sprintf("  \"%s\" . ", message)
+	lineLength := len(lineStr)
+
+	// populate lines with color coding
+	lineInColor := fmt.Sprintf("  \"%s\" . ", cyan(message))
+	maxContentWidth := lineLength
+
+	terminal, err := ts.GetSize()
+	if err != nil {
+		globalJSONFlag = true
+		return ""
+	}
+	var msg string
+	switch {
+	case len(lineStr) > terminal.Col():
+		msg = lineInColor
+	default:
+		// on windows terminal turn off unicode characters
+		var top, bottom, sideBar string
+		if runtime.GOOS == "windows" {
+			top = yellow("*" + strings.Repeat("*", maxContentWidth) + "*")
+			bottom = yellow("*" + strings.Repeat("*", maxContentWidth) + "*")
+			sideBar = yellow("|")
+		} else {
+			// color the rectangular box, use unicode characters here
+			top = yellow("┏" + strings.Repeat("━", maxContentWidth) + "┓")
+			bottom = yellow("┗" + strings.Repeat("━", maxContentWidth) + "┛")
+			sideBar = yellow("┃")
+		}
+
+		// construct the final message
+		msg = top + "\n" +
+			sideBar + lineInColor + sideBar + "\n" +
+			bottom
+	}
+	return msg
+}