Add additional clover coverage features

[veewee]

Q	A
Branch	master
Bug fix?	no
New feature?	yes
BC breaks?	no
Deprecations?	yes
Documented?	yes
Fixed tickets

This task introduces some additional features:

clover_coverage

grumphp:
    tasks:
        clover_coverage:
            clover_file: clover.xml
            minimum_level: 70
            target_level: 100

This task now has the possibility to:

• Optional target_level in case you want to upgrade gradually in a non-blocking way, whilst keeping track of the current status in the command output.

phpunit

This task got new coverage settings that work the same as in the paratest task:

grumphp:
    tasks:
        phpunit:
            coverage-clover: null
            coverage-html: null
            coverage-php: null
            coverage-xml: null

In case you want to combine the coverage report from multiple sources into 1 clover XML file, you can use following grumphp extension:
https://github.com/phpro/grumphp-combined-coverage-extension/

Example usage

grumphp:
    tasks:
        paratest:
            config: phpunit.xml.dist
            testsuite: unit
            coverage-php: cov/unit.cov
        phpunit:
            config_file: phpunit.xml.dist
            testsuite: functional
            coverage-php: cov/functional.cov
        clover_coverage:
            clover_file: "coverage-all.xml"
            minimum_level: 80
            target_level: 100
            metadata:
                priority: -100

Example output:

GrumPHP is sniffing your code!

Running tasks with priority 0!
==============================

Running task 1/2: paratest... ✔
Running task 2/2: phpunit... ✔

Running tasks with priority -100!
=================================

Running task 1/1: clover_coverage... ✘

       _    _ _                         _ _
      / \  | | |   __ _  ___   ___   __| | |
     / _ \ | | |  / _` |/ _ \ / _ \ / _` | |
    / ___ \| | | | (_| | (_) | (_) | (_| |_|
   /_/   \_\_|_|  \__, |\___/ \___/ \__,_(_)
                  |___/


clover_coverage
===============

Code coverage is 90%, which is below the target 100%

> echo $?
0

❗ Deprecations ❗

level is deprecated and will be removed in v3.0: change option to minimum_level.

grumphp:
    tasks:
        clover_coverage:
-            level: 30
+            minimum_level: 30