Cleanup travis

.travis.yml

@@ -1,10 +1,9 @@
-language: r
-cache: packages
-
-before_script:
-  - chmod +x ./_build.sh
-  - chmod +x ./_deploy.sh
+language: R
+cache:
+  packages: true
+  directories:
+  - _book
 
 script:
-  - ./_build.sh
-  - ./_deploy.sh
+  - Rscript -e "bookdown::render_book('index.Rmd', 'bookdown::gitbook')"
+	- Rscript -e "bookdown::render_book('index.Rmd', 'bookdown::pdf_book')"