Now Travis also fails on errors

Travis was failing only on `failed` tests, now it also includes `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()'