remove the IGA model,it uses some data that we cant share publicly,Adya reported

Author: zhangzhanqun

examples/IGA/README.txt

@@ -31,7 +31,6 @@
 dem_coupling = os.path.join(_module_path, "icfd", "dem_coupling")
 sloshing = os.path.join(_module_path, "icfd", "sloshing")
 
-iga_sample = os.path.join(_module_path, "iga", "iga_sample")
 camry_rc = os.path.join(_module_path, "implicit", "camry_rc")
 sale_efp = os.path.join(_module_path, "sale", "sale_efp")
 isph_rigidtest = os.path.join(_module_path, "isph", "rigidtest")