Fix git-check task and wrong gulp init command

README.md

@@ -33,7 +33,7 @@ To use this project as is, first clone the repo from GitHub, then run:
 $ cd ionic-app-base
 $ sudo npm install -g cordova ionic gulp
 $ npm install
-$ gulp init
+$ gulp install
 ```
 
 ## Using Sass (optional)

gulpfile.js

@@ -37,7 +37,7 @@ gulp.task('install', ['git-check'], function() {
 });
 
 gulp.task('git-check', function(done) {
-  if (sh.which('git')) {
+  if (!sh.which('git')) {
     console.log(
       '  ' + gutil.colors.red('Git is not installed.'),
       '\n  Git, the version control system, is required to download Ionic.',