Fix README link to debian/ubuntu build script

Fixes #211 #213

Author: JazzCore

README.rst

@@ -35,7 +35,7 @@ Installation
 
 	$ brew install homebrew/cask/wkhtmltopdf
 
-**Warning!** Version in debian/ubuntu repos have reduced functionality (because it compiled without the wkhtmltopdf QT patches), such as adding outlines, headers, footers, TOC etc. To use this options you should install static binary from `wkhtmltopdf <http://wkhtmltopdf.org/>`_ site or you can use `this script <https://github.com/JazzCore/python-pdfkit/blob/master/travis/before-script.sh>`_.
+**Warning!** Version in debian/ubuntu repos have reduced functionality (because it compiled without the wkhtmltopdf QT patches), such as adding outlines, headers, footers, TOC etc. To use this options you should install static binary from `wkhtmltopdf <http://wkhtmltopdf.org/>`_ site or you can use `this script <https://github.com/JazzCore/python-pdfkit/blob/master/ci/before-script.sh>`_ (written for CI servers with Ubuntu 18.04 Bionic, but it could work on other Ubuntu/Debian versions).
 
 * Windows and other options: check wkhtmltopdf `homepage <http://wkhtmltopdf.org/>`_ for binary installers