Merge pull request #90 from UCL-HIC/fixTravis

Now Travis also fails on errors

.travis.yml

@@ -10,7 +10,7 @@ r_packages:
   - covr
 
 script:
-  - Rscript -e 'library(devtools); checkOutput <- data.frame(test()); if (sum(checkOutput["failed"]) > 0){q(status = 1, save = "no")}'
+  - Rscript -e 'library(devtools); checkOutput <- data.frame(test()); if (sum(checkOutput["failed"]) + sum(checkOutput[["error"]]) > 0){q(status = 1, save = "no")}'
 
 after_success:
   - Rscript -e 'library(covr); codecov()'