Updated Implementation Framework

Updated to cover changes made by Dan to Master regarding general design changes

Also added remove_two_worst survivor selection method

src/fitness_function/fitness_examples.py

@@ -0,0 +1,16 @@
+class Fitness_Examples:
+    """Fitness function examples used"""
+    def is_it_5(self, chromosome):
+        """A very simple case test function - If the chromosomes gene value is a 5 add one
+         to the chromosomes overall fitness value."""
+        # Overall fitness value
+        fitness = 0
+        # For each gene in the chromosome
+        for gene in chromosome.gene_list:
+            # Check if its value = 5
+            if(gene.value == 5):
+                # If its value is 5 then add one to
+                # the overal fitness of the chromosome.
+                fitness += 1
+                
+        return fitness