docs(readme): remove dead gittip links

Also stop caching node_modules on travis-ci

Author: dalelotts

.travis.yml

@@ -1,8 +1,5 @@
 sudo: required
 language: node_js
-cache:
-  directories:
-    - node_modules
 notifications:
   email: false
 node_js:

README.es_MX.md

@@ -229,13 +229,5 @@ angular-bootstrap-datetimepicker fué liberada con la licencia MIT y copyright 2
 
 La licencia completa de angular-bootstrap-datetimepicker se encuentra [en el repositorio del proyecto](LICENSE) para más información.
 
-## Donativos
-Puedes apoyar este proyecto y otros relizados por Dale Lotts por medio de [gittip][gittip-dalelotts].
-
-[![Apoya via Gittip][gittip-badge]][gittip-dalelotts]
-
-[gittip-badge]: https://rawgithub.com/twolfson/gittip-badge/master/dist/gittip.png
-[gittip-dalelotts]: https://www.gittip.com/dalelotts/
-
 [license-image]: http://img.shields.io/badge/license-MIT-blue.svg?style=flat
 [license-url]: LICENSE

README.md

@@ -239,13 +239,5 @@ angular-bootstrap-datetimepicker is released under the MIT license and is copyri
 The full angular-bootstrap-datetimepicker license is located [in the project repository](LICENSE) for more information.
 
 
-## Donating
-Support this project and other work by Dale Lotts via [gittip][gittip-dalelotts].
-
-[![Support via Gittip][gittip-badge]][gittip-dalelotts]
-
-[gittip-badge]: https://rawgithub.com/twolfson/gittip-badge/master/dist/gittip.png
-[gittip-dalelotts]: https://www.gittip.com/dalelotts/
-
 [license-image]: http://img.shields.io/badge/license-MIT-blue.svg?style=flat
 [license-url]: LICENSE