How can I add a taxonomy terms as a CSS class to my views?
You can add a field with the taxonomy term and then exclude it from the view. 

Then add as many fields you wish to present, such as Title.

Finally, add a global: custom text, and specify for example:

&lt;div class="[field_tags]"&gt;[title]&lt;/div&gt;


Replace with your field names obviously. You can consult the "replacement patterns" that the Views module kindly provides.