clean trailing spaces

   * `find . -name "*.py" | xargs -I{} sed -i 's/ *$//g' {}`
Merge branch 'clean' into dev
point doc to readthedocs
travis
remove quote added by the editor...
add CI branches
remove the cd at end of test

   * This cd will return 0, resulting in false report
apply patch 0555, i.e. commit 8c5050f407829186e25 for CI
remove Python 3
add travis CI status links
Merge branch 'master' into dev