Add distributed tuning test

Author: lhnguyen-vn

test/Project.toml

@@ -1,5 +1,6 @@
 [deps]
 ComputationalResources = "ed09eef8-17a6-5b46-8889-db040fac31e3"
+Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
 Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
 EvoTrees = "f6006082-12f8-11e9-0c9c-0d5d367ab1e5"
 MLJBase = "a7f614a8-145f-11e9-1d2a-a57a1082229d"

test/runtests.jl

@@ -1,12 +1,17 @@
-using MLJParticleSwarmOptimization
-using Random
-using Test
-using ComputationalResources
-using Distributions
-using EvoTrees
-using MLJBase
-using MLJTuning
-using StableRNGs
+using Distributed
+addprocs(2)
+
+@everywhere begin
+    using MLJParticleSwarmOptimization
+    using Random
+    using Test
+    using ComputationalResources
+    using Distributions
+    using EvoTrees
+    using MLJBase
+    using MLJTuning
+    using StableRNGs
+end
 
 const PSO = MLJParticleSwarmOptimization