Fix check warning: 'qpdf' is needed for checks on size reduction of PDFs

.gitlab-ci.yml

@@ -26,7 +26,7 @@ test:
   script:
   - mkdir -p $R_LIBS_USER $BUILD_LOGS_DIR
   # system requirements
-  - apt-get install -y libv8-dev libjq-dev libprotobuf-dev protobuf-compiler libgdal-dev libproj-dev libudunits2-dev
+  - apt-get install -y libv8-dev libjq-dev libprotobuf-dev protobuf-compiler qpdf libgdal-dev libproj-dev libudunits2-dev
   - R -e 'devtools::install_deps(dep = T, lib = Sys.getenv("R_LIBS_USER"))'
   - echo $R_LIBS_USER
   - R -e 'Sys.getenv("R_LIBS_USER")'

DESCRIPTION

 Package: mapMCDA
 Title: Produce an epidemiological risk map by weighting multiple risk
         factors
-Version: 0.4.36
-Date: 2020-04-18
+Version: 0.4.37
+Date: 2020-04-19
 Authors@R: c( person("Andrea", "Apolloni", email =
         "andrea.apolloni@cirad.fr", role = c("ctb"), comment = "Animal
         mobility algorithm"), person("Elena", "Arsevska", email =