update package locations to a subdir packages

packages/cplint/examples/school_simple.uni

@@ -0,0 +1,18 @@
+universe(['Stu'],[s0]).
+universe(['Key'],[r0,r1]).
+universe(['Cou'],[c16,c10]).
+
+type(stu,[s0]).
+type(reg,[r0,r1]).
+type(cou,[c16,c10]).
+type(gr,[1,4]).
+type(dif,[h,l]).
+type(ran,[h,l]).
+
+mode(registration(reg,cou,stu)).
+mode(registration_grade(reg,gr)).
+mode(registration_course(reg,cou)).
+mode(registration_student(reg,stu)).
+mode(course_difficulty(cou,dif)).
+mode(student_ranking(stu,ran)).
+