changed python2 print statements to python3 in 07_dijkstras_algorithm (#82)

* Resolve Issue #40: Changed more examples to use python3 syntax

* corrected selection sort python

* 07 dijkstras changed python2 print statement

07_dijkstras_algorithm/python/01_dijkstras_algorithm.py

@@ -61,6 +61,6 @@ while node is not None:
     # Find the next node to process, and loop.
     node = find_lowest_cost_node(costs)
 
-print "Cost from the start to each node:"
-print costs
+print("Cost from the start to each node:")
+print(costs)