Allow v0.3 to read v0.2 instance files

test/transform/initcond_test.jl

@@ -4,12 +4,9 @@
 
 using UnitCommitment, Cbc, JuMP
 
-basedir = @__DIR__
-
 @testset "generate_initial_conditions!" begin
     # Load instance
-    instance =
-        UnitCommitment.read("$basedir/../fixtures/case118-initcond.json.gz")
+    instance = UnitCommitment.read("$FIXTURES/case118-initcond.json.gz")
     optimizer = optimizer_with_attributes(Cbc.Optimizer, "logLevel" => 0)
 
     # All units should have unknown initial conditions

test/transform/slice_test.jl

@@ -5,7 +5,7 @@
 using UnitCommitment, LinearAlgebra, Cbc, JuMP, JSON, GZip
 
 @testset "slice" begin
-    instance = UnitCommitment.read_benchmark("test/case14")
+    instance = UnitCommitment.read("$FIXTURES/case14.json.gz")
     modified = UnitCommitment.slice(instance, 1:2)
 
     # Should update all time-dependent fields