Change CONFIGURE_OPTS

 - Use CONFIGURE_OPTS as array
 - Check for both ruby-2.4 and ruby-2.5

Author: d-unsed

build.sh

@@ -201,11 +201,16 @@ ruby-*)
     EXTRA_FLAGS="--rubygems ignore"
   fi
 
-  if [[ $RUBY = ruby-2.4* ]]; then
-    EXTRA_CONFIGURE_OPTS=",--enable-install-static-library"
-  fi
+  CONFIGURE_OPTS_ARRAY=( --without-tcl --without-tk --without-gmp )
+
+  case $RUBY in
+  ruby-2.4*|ruby-2.5*)
+    CONFIGURE_OPTS_ARRAY+=( --enable-install-static-library );;
+  esac
+
+  CONFIGURE_OPTS=$( IFS=','; echo "${CONFIGURE_OPTS_ARRAY[*]}" )
 
-  announce rvm install $RUBY $EXTRA_FLAGS --verify-downloads 1 $MOVABLE_FLAG --disable-install-doc -C --without-tcl,--without-tk,--without-gmp$EXTRA_CONFIGURE_OPTS;;
+  announce rvm install $RUBY $EXTRA_FLAGS --verify-downloads 1 $MOVABLE_FLAG --disable-install-doc -C $CONFIGURE_OPTS;;
 jruby-head)
   update_mvn 3.3.9
   announce rvm install $RUBY --verify-downloads 1;;