Integration of pronto required to add few new gems and to update some of
the gems. The old method which provided the linter launching was
reworked to launch pronto which provide the linter launching. The output
of pronto is the result of all linters. The pronto result is transformed
into a structure which match the original one. This integration required
to change few tests and add new ones.

Closes ManageIQ#192

Request in ManageIQ#406 to remove files in lib/linter/ which are not used

Variable "inspected_file_count" in the result of the linters has been removed due to missing use. It was not used in the pull request comment describing the offenses detected by linters in the source code.

Pronto runners (linters) expected to run will be automatically required in the CodeAnalysisMixin based on Gemfile specifications for pronto runners (linters).

This makes use of the newly working (I hope) Repo#git_fetch, as well as
removes some of the `mktmpdir` logic that shouldn't be required because
we are using Rugged.

This pulls back in some deleted code to handle errors with the Rubocop
linter (but sets up a pattern for it moving forward).

Our configs for manageiq-ui-classic (which I am using for testing)
require newer versions of Rubocop configs to function, so to facilitate
the, I have included `manageiq-style` into this repo for testing this
PR.  Might be required moving forward, but this is just for testing for
now.

Right now, what ever is on the "fetched master" for the linter configs
will be what is used by Pronto, and not what is up to date with the
branch being checked against.

This "attempts" to generate a config based on the git blob for the
branch we are checking, but it is still not quite working.