cleaned up linting block in test.sh

.ci/test.sh

@@ -50,27 +50,25 @@ if [[ $TRAVIS == "true" ]] && [[ $TASK == "check-docs" ]]; then
     exit 0
 fi
 
-if [[ $TASK == "lint" ]]; then
+if [[ $TRAVIS == "true" ]] && [[ $TASK == "lint" ]]; then
     conda install -q -y -n $CONDA_ENV \
         pycodestyle \
         pydocstyle
     pip install --user cpplint
     echo "Linting Python code"
     pycodestyle --ignore=E501,W503 --exclude=./compute,./.nuget . || exit -1
     pydocstyle --convention=numpy --add-ignore=D105 --match-dir="^(?!^compute|test|example).*" --match="(?!^test_|setup).*\.py" . || exit -1
-
-    # stringi and r-lintr
-    echo "Linting R code"
+    # stringi needs to be installed separate from r-lintr
+    # to avoid issues like 'unable to load shared object stringi.so'
     conda install -y -n $CONDA_ENV \
         r-stringi
     conda install -y -n $CONDA_ENV \
         -c conda-forge \
             r-lintr>=2.0
+    echo "Linting R code"
     Rscript ${BUILD_DIRECTORY}/.ci/lint_r_code.R ${BUILD_DIRECTORY} || exit -1
-
     echo "Linting C++ code"
     cpplint --filter=-build/c++11,-build/include_subdir,-build/header_guard,-whitespace/line_length --recursive ./src ./include || exit 0
-
     exit 0
 fi