Added tests to dateTime utility getDayName method

spec/javascripts/datetime_utility_spec.js.coffee

+#= require lib/utils/datetime_utility
+
+describe 'Date time utils', ->
+  describe 'get day name', ->
+    it 'should return Sunday', ->
+      day = gl.utils.getDayName(new Date('07/17/2016'))
+      expect(day).toBe('Sunday')
+
+    it 'should return Monday', ->
+      day = gl.utils.getDayName(new Date('07/18/2016'))
+      expect(day).toBe('Monday')
+
+    it 'should return Tuesday', ->
+      day = gl.utils.getDayName(new Date('07/19/2016'))
+      expect(day).toBe('Tuesday')
+
+    it 'should return Wednesday', ->
+      day = gl.utils.getDayName(new Date('07/20/2016'))
+      expect(day).toBe('Wednesday')
+
+    it 'should return Thursday', ->
+      day = gl.utils.getDayName(new Date('07/21/2016'))
+      expect(day).toBe('Thursday')
+
+    it 'should return Friday', ->
+      day = gl.utils.getDayName(new Date('07/22/2016'))
+      expect(day).toBe('Friday')
+
+    it 'should return Saturday', ->
+      day = gl.utils.getDayName(new Date('07/23/2016'))
+      expect(day).toBe('Saturday')