Use import as to load MOI (#91)

Author: blegat

src/MOI_wrapper.jl

@@ -3,9 +3,7 @@
 # Use of this source code is governed by an MIT-style license that can be found
 # in the LICENSE.md file or at https://opensource.org/licenses/MIT.
 
-import MathOptInterface
-
-const MOI = MathOptInterface
+import MathOptInterface as MOI
 
 mutable struct Optimizer <: MOI.AbstractOptimizer
     objective_constant::Cdouble