Remove trailing whitespace in CMakeLists.txt

doc/cookbook/1-infiltration-sand/CMakeLists.txt

 
-dorie_add_metaini_test(TARGET dorie_test 
+dorie_add_metaini_test(TARGET dorie_test
                        METAINI tutorial-1.mini.in)
 
 configure_file(${CMAKE_CURRENT_BINARY_DIR}/tutorial-1.ini
-               ${CMAKE_CURRENT_SOURCE_DIR}/config.ini 
+               ${CMAKE_CURRENT_SOURCE_DIR}/config.ini
                COPYONLY)
 
 # Copy files needed for the test to run
-configure_file(${CMAKE_BINARY_DIR}/doc/default_files/2d_infiltr.bcdat 
+configure_file(${CMAKE_BINARY_DIR}/doc/default_files/2d_infiltr.bcdat
                2d_infiltr.bcdat
                COPYONLY)
-configure_file(${CMAKE_BINARY_DIR}/doc/default_files/richards_param.yml 
+configure_file(${CMAKE_BINARY_DIR}/doc/default_files/richards_param.yml
                richards_param.yml
-               COPYONLY)
\ No newline at end of file
+               COPYONLY)