formatting readme file

Signed-off-by: David A. Cuadrado <krawek@gmail.com>

README.rdoc

@@ -4,19 +4,19 @@ Ruby library to access the Authy API
 
 == Usage
 
-require 'authy'
+    require 'authy'
 
-Authy.api_key = 'your-api-key'
-Authy.api_uri = 'http://test-authy-api.heroku.com/'
-Authy::API.register_user(:user => {:email => 'your@email.com'})
-Authy::API.verify(:id => 'your-device-id', :otp => 'current-otp')
+    Authy.api_key = 'your-api-key'
+    Authy.api_uri = 'http://test-authy-api.heroku.com/'
+    Authy::API.register_user(:user => {:email => 'your@email.com'})
+    Authy::API.verify(:id => 'your-device-id', :otp => 'current-otp')
 
 Available calls:
 
-  #register_user
-  #moving_factor
-  #register_device
-  #verify
+    #register_user
+    #moving_factor
+    #register_device
+    #verify
 
 == Contributing to authy