Added test for proper handling of put!/get priorities

* Added a test that checks if put!/get requests are handled in order of descending priority, as requested by @Krastanov in the discussion of PR #101. This test will currently fail!

Author: jvkerckh

test/test_resource_priorities.jl

@@ -56,4 +56,21 @@ put!(sto, :b; priority = 6.0)
 put!(sto, :b; priority = BigInt(5))
 put!(sto, :b; priority = typemin(UInt))
 @show sto.items
-@show keys(sto.put_queue)
+@show keys(sto.put_queue)
+
+@testset "Resource priority evaluation" begin
+  using ResumableFunctions
+  
+  let sim = Simulation()
+    @resumable function f(env, res)
+      @yield lock(res)
+    end
+    
+    res = Resource(sim)
+    ev1 = unlock(res, priority=5)
+    ev2 = unlock(res)
+    @process f(sim, res)
+    run(sim)
+    @test state(ev1) === ConcurrentSim.processed
+  end
+end