Addressing review comments, Deleting unintentional file and used FAILURE constant in ClientTest as well

1) Updated test cases to use Junit Assert method as compared to assert keyword 2) Proper testing of RemoteService using RandomProvider interface. Introduced RandomProvider interface so that randomness can be controlled from test cases. 3) For readability used constant for representing FAILURE

Fix redundant list alloc in LotteryNumbers

Delete & Ignore output.txt & error.txt

#781 Resolved ClasscastException from Acyclic Visitor

Both output.txt and error.txt are produced by tests.
Each file contained a header that was overridden upon executing said
tests causing tracked files to be changed.

Added them to a local .gitignore file for this module.

Execute Around - use lambda

#564: Collection Pipeline pattern

#778: Binary Search Tree Iterator

Use try-with-resources

Refactored App.java to remove duplicate code and elegantly demonstrate each implementation of the Iterator interface. Removed the redundant ItemIterator interface. Added insert() method to TreeNode class to allow for more elegant construction of BSTs.

Replace try statements that close a resource in the finally block with a
try-with-resources statement [1].

This commit was created automatically by Diffblue refactorings (https://www.diffblue.com/).

[1] https://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html

Fixed minor changes suggested by Checkstyle

Fix converter image Display Issue

First proposal for #586 Hexagonal Architecture primary ports should have interfaces

#778 Implemented BSTIterator. Included comprehensive unit and integration tests. Refactored file structure to be friendly to future contributors with iterators of more data structures. Added JUnitPlatform to enable running test suite across all iterator implementations. Added README to /binarysearchtree to document what it does and how it works.

# Conflicts:
#	pom.xml

Add an 'Override' annotaion