replaced travis script with ci/test.sh
replaced travis install
enabled apt cache & set python packages to system instead of virtual python
making everything tidy & up-to-date
 - updated ci/test.sh with the latest tests (rebase) after merging #96
 - removed obsolete stuff from ci/install.sh
 - now installing numpy and cython instead of compiling it (speedup!)
Merge pull request #99 from kreczko/travis_scripts

Replacing travis-ci.org scripts