Solution#1
Run composer global self-update
Solution#2
Update laravel installer version first. To do this, change the version required in ~/config/composer/composer.json from ^1.3 to dev-master, then run composer update laravel/installer
.
Now run laravel new lara55
again. It should work
Solution#3
Step 1 - composer self-update
Step 2 - composer global require "laravel/installer"
Run sudo apt-get -y install php5-mysql
The requested PHP extension ext-curl * is missing from your system. Install or enable PHP's curl extension
Run sudo apt-get install php5-curl