Allow HTML style attribute for filtred HTML
go to admin/config/content/formats/filtered_html 



In the limit allowed HTML tags, add the tags that you need. You could view source to see what tags are being added when you're trying to font-size and text align and then add them here.

go to: 

/admin/config/content/ckeditor/edit/Advanced (for Filter HTML)

Then under Advanced Content Filter, select disabled.