Cache pip and sign commit

.travis.yml

@@ -5,7 +5,8 @@ install:
 - source ./support/texlive_install.sh
 - pip install PyGithub
 cache:
-  directories:
+- pip
+- directories:
   - "/tmp/texlive"
   - "$HOME/.texlive"
 script:

support/commitUp.sh

@@ -4,6 +4,6 @@ gpg --import bibbot.asc
 git config --global user.email "bibbot@ckurs.de"
 git config --global user.name "BibBot"
 git config --global user.signingkey "1617C27854592471"
-git commit -m "Reformat bib file" gipp.bib
+git commit -S -m "Reformat bib file" gipp.bib
 git remote add http https://${GITHUB_TOKEN}@github.com/ag-gipp/bib.git
 git push http HEAD:$TRAVIS_BRANCH