Fix travis.yml

Author: jfisher-usgs

.travis.yml

@@ -6,14 +6,11 @@ r:
   - release
   - devel
 
+r_build_args: --no-build-vignettes --no-manual --no-resave-data
+r_check_args: --no-build-vignettes --no-manual
+
 addons:
   apt:
     packages:
       - libgdal-dev
       - libproj-dev
-
-r_github_packages:
-  - jimhester/covr
-
-after_success:
-  - Rscript -e 'covr::coveralls()'