renamed stringbuilder variable

* Add additional luhn test for fuller coverage as in #972

* Replace unnecessary test and add comment for future maintainers.

* Add link to issue #972 in Luhn tests

* Update luhn test formatting.

* Add topics to House as per #793.

* Amend 'house' topics in config.json

* Remove tag 'variables' from house topics.

* Add topic to pythagorean-triplet

* cr feedback

* Update config.json

* Update config.json

Attempt to fix space issue.

queen-attack: update to v2.0.0

* Add topics for OCR Numbers exercise

* Limit list to 5 relevant topics

https://github.com/exercism/problem-specifications/commit/44a1e12aedb1a9acff3ee79c0413ecf3093401a6#diff-96b36309ff1b4f05ed51e0af6563ed56

Normalize the config file to minimize noise later

We will be scripting a number of changes to the track configuration.
This runs configlet fmt, which ensures that any further changes can be minimized.

Add script for checking for exercise updates

secret-handshake: update to v1.1.0

perfect-numbers: update version file

bracket-push: update to v1.1.0

collatz-conjecture: update version file

* #347 - Rework the "About the Java Track" page 

Page re-written to be more friendly and accessible.

* Rework the "About the Java Track" page

Rework the "About the Java Track" page
Page re-written to be more friendly and accessible.

* Rework the "About the Java Track" page

Rework the "About the Java Track" page.
Page re-written to be more friendly and accessible, included suggestions made by FridaTveit.

https://github.com/exercism/problem-specifications/commit/69c8700e75700e6a8e4f012caae8c547519874d7#diff-54ab3721bf1c4fe66726b1e78c24bea1

https://github.com/exercism/problem-specifications/commit/924bb7a18a9e641704c9add4618a906be5f83e66#diff-bd8ec80846507aec0eb2168f61697d0b

https://github.com/exercism/problem-specifications/commit/855c59149e6ba66c3c0495888cef203fcc231960#diff-8257653ce323d3cbdfb5ecf45b0e0d93

Test change was removing whitespace from test name, which does not
affect the Java test suite since we write it by hand.

Add missing version files

* bank-account: added topics

* minor changes

binary-search-tree: use generics

Adjust exercise README formatting; drop help link

* issue fixed

* minor bug fixed

* #941 fixed

* #941 fixed

* triangle: topics added

Rename .version files

binary-search: use generics

custom-set: use generics and tidy up tests

Update new exercise guide to mention version file

* '#925-addTopics'

* added topic for spiral-matrix

* added topic for spiral-matrix

* Update config.json

Since the class signature is rather complicated, starter implementation
should be provided.

Also tidied up the reference implementation.

Add topics to list-ops exercise