improve cran-comments, fix #175, skip-ci

Author: Andrea Gilardi

cran-comments.md

@@ -1,9 +1,11 @@
 ## Release summary
 
 This is a minor release. We modified several examples and tests to fix the
-errors reported by CRAN checks a few days ago: 
+errors reported by CRAN checks a few days ago:
 https://cran.rstudio.org/web/checks/check_results_osmextract.html
 
+Tests and examples write only in the R sessions's temporary directory.
+
 ## Test environments
 - local Windows install, R 3.6.3
 - R-hub windows-x86_64-devel (r-devel)