improve scrutinizer config

[hgraca]

add the following to the scrutinizer config

build:
    dependencies:
        before:
            - composer install -d instapro --no-scripts

    nodes:
        analysis:
            project_setup:
                override: true
            tests:
                override:
                    - php-scrutinizer-run --enable-security-analysis

filter:
  paths:
    - "src/"
  dependency_paths:
    - "vendor/"

build_failure_conditions:
    - 'issues.new.exists'
    - 'project.metric_change("scrutinizer.test_coverage", < -0.05)'