Unit testing for def/ module.

Added unit tests to test code in def/ module.

def/sortingCriteria_test.go

@@ -0,0 +1,31 @@
+// Copyright (C) 2018 spdf
+//
+// This file is part of Elektron.
+//
+// Elektron is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Elektron is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Elektron.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+package def
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestSortingCriteria(t *testing.T) {
+	task := &Task{CPU: 1.0, RAM: 1024.0, Watts: 50.0}
+	assert.Equal(t, 1.0, SortByCPU(task))
+	assert.Equal(t, 1024.0, SortByRAM(task))
+	assert.Equal(t, 50.0, SortByWatts(task))
+}