Implement 'osnadmin channel info' subcommand and update tests

Signed-off-by: Priyansu Rout <priyansurout192004@gmail.com>

cmd/osnadmin/main.go

@@ -58,7 +58,7 @@ func executeForArgs(args []string) (output string, exit int, err error) {
 	infoChannelID := info.Flag("channelID", "Channel ID").Short('c').Required().String()
 
 	remove := channel.Command("remove", "Remove a channel from an Ordering Service Node (OSN).")
-	removeChannelID := remove.Flag("channelID", "Channel ID").Short('c').String()
+	removeChannelID := remove.Flag("channelID", "Channel ID").Short('c').Required().String()
 
 	command, err := app.Parse(args)
 	if err != nil {

cmd/osnadmin/main_test.go

@@ -209,6 +209,20 @@ var _ = Describe("osnadmin", func() {
 			}, nil)
 		})
 
+		It("returns an error when channelID flag is not provided", func() {
+			args := []string{
+				"channel",
+				"info",
+				"--orderer-address", ordererURL,
+				"--ca-file", ordererCACert,
+				"--client-cert", clientCert,
+				"--client-key", clientKey,
+			}
+			output, exit, err := executeForArgs(args)
+			expectedErrorMessage := "required flag(s) \"channelID\" not set"
+			checkCLIError(output, exit, err, expectedErrorMessage)
+		})
+
 		It("uses the channel participation API to list the details of a single channel", func() {
 			args := []string{
 				"channel",