warn user of typos

lib/cmd.js

@@ -1,5 +1,6 @@
 const program = require('commander');
 const promptly = require('promptly');
+const propose = require('propose');
 const Embark = require('../lib/index');
 let embark = new Embark;
 
@@ -169,8 +170,13 @@ class Cmd {
 
   otherCommands() {
     program
-      .action(function (env) {
-        console.log('unknown command "%s"'.red, env);
+      .action(function (cmd) {
+        console.log('unknown command "%s"'.red, cmd);
+        let dictionary = ['new', 'demo', 'build', 'run', 'blockchain', 'simulator', 'test', 'upload', 'version' ];
+        let suggestion = propose(cmd, dictionary, {threshold: 0.3});
+        if (suggestion) {
+          console.log('did you mean "%s"?'.green, suggestion);
+        }
         console.log("type embark --help to see the available commands");
         process.exit(0);
       });

package.json

@@ -41,6 +41,7 @@
     "orbit-db": "^0.17.3",
     "parse-json": "^4.0.0",
     "promptly": "^2.1.0",
+    "propose": "0.0.5",
     "serve-static": "^1.11.1",
     "shelljs": "^0.5.0",
     "solc": "0.4.17",