Codacy should not forbid the use of head or last on scala collections in Unit Tests

[rodoherty1]

Expected behaviour:

The use of .head or .last may yield an exception if the collection is empty.
In unit tests, however, head and last should perhaps be permitted.
Codacy flags the use of head and last in Unit Tests as a slide in code quality.

Actual behaviour:

Codacy should perhaps allow *.spec to use .head and .last without flagging these as a slide in code quality.

Steps to reproduce behaviour:

It should be possible to obtain a codacy report from the sbt shell:

$ sbt
> clean
> coverage
> test
> coverageReport
> coverageAggregate
> codacyCoverage

This github issue depends on completion of Issue 25