[breaking] a large refactoring of MathOptIIS (#34)

This commit is breaking because it:

 * Removes SkipFeasibilityCheck
 * Removes StopIfInfeasibleBounds
 * Removes StopIfInfeasibleRanges
 * Removes DeletionFilter
 * Removes ElasticFilterTolerance
 * Removes ElasticFilterIgnoreIntegrality

In addition, this commit will likely result in a different IIS being
returned for many models because it now exploits an infeasibility
certificate if one is present.

Author: odow

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ jobs:
       fail-fast: false
       matrix:
         machine:
-          - version: '1.6'
+          - version: '1.10'
             os: ubuntu-latest
             arch: x64
           - version: '1'
@@ -41,7 +41,7 @@ jobs:
         with:
           version: ${{ matrix.machine.version }}
           arch: ${{ matrix.machine.arch }}
-      - uses: julia-actions/cache@v2
+      - uses: julia-actions/cache@v3
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
       - uses: julia-actions/julia-processcoverage@v1

Project.toml

@@ -7,4 +7,4 @@ MathOptInterface = "b8f27783-ece8-5eb3-8dc8-9495eed66fee"
 
 [compat]
 MathOptInterface = "1.43.0"
-julia = "1.6"
+julia = "1.10"

README.md

@@ -27,7 +27,7 @@ Pkg.add("MathOptIIS")
 
 ## Usage
 
-This package is not intended to be called directly from user-code. Instead, it
+MathOptIIS is not intended to be called directly from user-code. Instead, it
 should be added as a dependency to solver wrappers that want to provide an IIS.
 
 To add to an existing wrapper, add a new field:
@@ -41,6 +41,11 @@ function MOI.compute_conflict!(model::Optimizer)
     solver = MathOptIIS.Optimizer()
     MOI.set(solver, MathOptIIS.InfeasibleModel(), model)
     MOI.set(solver, MathOptIIS.InnerOptimizer(), Optimizer)
+    # Optional: set the solver's silent to true or false. In this example,
+    # follow the outer attribute.
+    MOI.set(solver, MOI.Silent(), MOI.get(model, MOI.Silent()))
+    # Optional: set a time limit. In this case, 60 seconds.
+    MOI.set(solver, MOI.TimeLimitSec(), 60.0)
     MOI.compute_conflict!(solver)
     model.conflict_solver = solver
     return
@@ -53,6 +58,13 @@ function MOI.get(optimizer::Optimizer, attr::MOI.ConflictStatus)
     return MOI.get(optimizer.conflict_solver, attr)
 end
 
+function MOI.get(optimizer::Optimizer, attr::MOI.ConflictCount)
+    if optimizer.conflict_solver === nothing
+        return 0
+    end
+    return MOI.get(optimizer.conflict_solver, attr)
+end
+
 function MOI.get(
     optimizer::Optimizer,
     attr::MOI.ConstraintConflictStatus,