Build jq from source.

- we need version 1.5 and can't get it from the official repo.
- includes adjusting the PATH so that our tools (like jq) get
  precedence.

Issue #306: fix spelling mistakes in test names

Migrate to JUnit @Rule in triangle exercise [Fix #268]

Nucleotide-count: use JUnit's @Rule feature [Fix #264]

Pascals-triangle: use JUnit's @Rule feature [Fix #265]

Simple-linked-list: use JUnit's @Rule feature [Fix #267]

Nth-prime: use JUnit's @Rule feature [Fix #263]

Series: use JUnit's @Rule feature [Fix #266]

Allergies: remove redundant array creation [Fix #275]

Change @Test expected parameter to @Rule ExpectedException in hamming [Fix #262]

Change test names to Camel case

luhn: update to latest canonical tests

Issue #154: make journey-test.sh use exercises

Issue #276: linked-list: Rename Deque to DoublyLinkedList

Previously this code was applying the required operations to every
second digit starting from the LEFT. The correct solution applies the
required operations to every second digit starting from the RIGHT. The
fact that this was not caught by the tests is a problem! The canonical
tests have been updated since this exercise was last overhauled, so next
steps should be to update to match the expanded canonical test suite,
then test against a broken implementation to see if it is now caught.
Even if it is, it may be worth including an explicit left vs right test
in the canonical suite if one does not already exist.

Issue #261: Bring phone-number exercise in to compliance with canonical data

Issue #284: add Ignore annotation to etl tests

* hello-world: Modify tests to reject name == "" comparison

* hello-world: Add emptyStringIsComparedByValue() test case

perfect-numbers: add to track

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