add sat inferface to the linear solver wrapper

ortools/linear_solver/samples/integer_programming_example.py

@@ -15,6 +15,7 @@
 from __future__ import print_function
 # [START import]
 from ortools.linear_solver import pywraplp
+
 # [END import]
 
 

ortools/linear_solver/samples/simple_lp_program.py

@@ -15,6 +15,7 @@
 # [START import]
 from __future__ import print_function
 from ortools.linear_solver import pywraplp
+
 # [END import]
 
 

ortools/linear_solver/samples/simple_mip_program.py

@@ -15,6 +15,7 @@
 # [START import]
 from __future__ import print_function
 from ortools.linear_solver import pywraplp
+
 # [END import]