makes "store-api-ey" a command

src/isn/Program.cs

@@ -46,7 +46,6 @@ namespace isn
 
         static readonly OptionSet pushoptions = new OptionSet {
                 { "k|api-key=", "use api key", val => apiKey = apiKey ?? val },
-                { "p|store-api-key", "store used api key", val => storApiKey = val != null },
                 { "s|source=", "use source", val => CurrentSource = CurrentSource ?? val },
                 { "h|help", "show this message and exit", h => shouldShowPushHelp = h != null },
             };
@@ -179,7 +178,7 @@ namespace isn
                 }
             };
 
-            var setapikey = new Command("set-api-key")
+            var setapikey = new Command("store-api-key", "Store this API key")
             {
                 Run = sargs => StoreApiKey(sargs)
             };

src/isn/commands/set-api-key.cs

@@ -9,14 +9,18 @@ namespace isn
    
     partial class Program
     {
-     
         private static void StoreApiKey(IEnumerable<string> storeArgs)
         {
             var args = storeoptions.Parse(storeArgs);
+            if (args.Count != 1)
+            {
+                Console.Error.WriteLine("StoreApiKey command takse one and only one argument, the key.");
+               shouldShowPushHelp=true;
+            }
             if (shouldShowPushHelp)
             {
                 // output the options
-                Console.Error.WriteLine("Push Options:");
+                Console.Error.WriteLine("StoreApiKey Options:");
                 storeoptions.WriteOptionDescriptions(Console.Out);
             }
             else