Minor code fixes.

Author: MrMatthewLayton

OnixLabs.Core.UnitTests/OptionalTests.cs

@@ -336,7 +336,7 @@ public void OptionalNoneGetValueOrDefaultShouldProduceExpectedResult()
 
         // Then
         Assert.Equal(0, actualNumber);
-        Assert.Equal(null, actualText);
+        Assert.Null(actualText);
     }
 
     [Fact(DisplayName = "Optional Some.GetValueOrDefault with default value should produce the expected result.")]

OnixLabs.Core.UnitTests/SpecificationTests.cs

@@ -163,10 +163,10 @@ public void PersonSpecificationNotShouldReturnExpectedResult()
         Specification<Person> specification = PersonSpecification.Or(
             new PersonNameStartsWithSpecification("A"),
             new PersonHasLocationCitySpecification("Lisbon")
-        ).Not();
+        );
 
         // When
-        IEnumerable<Person> result = Person.People.Where(specification).ToList();
+        IEnumerable<Person> result = Person.People.WhereNot(specification).ToList();
 
         // Then
         Assert.Single(result);