Add infection testing

Author: vukanac

.gitignore

@@ -4,3 +4,9 @@ composer.phar
 # Commit your application's lock file https://getcomposer.org/doc/01-basic-usage.md#commit-your-composer-lock-file-to-version-control
 # You may choose to ignore a library lock file http://getcomposer.org/doc/02-libraries.md#lock-file
 # composer.lock
+
+
+# In /build/ directory store all artefacts of infection etc.
+/build/
+# Ignore local infection overrides.
+infection.json

.travis.yml

@@ -11,6 +11,12 @@ cache:
 install:
   - composer install --no-interaction --prefer-source
 
+before_script:
+  - wget https://github.com/infection/infection/releases/download/0.8.0/infection.phar
+  - wget https://github.com/infection/infection/releases/download/0.8.0/infection.phar.pubkey
+  - chmod +x infection.phar
+
 script:
   - composer validate --strict
   - vendor/bin/phpunit
+  - ./infection.phar --min-msi=48 --threads=4

README.md

@@ -7,3 +7,22 @@ CI with PHP and TravisCI
 
     composer install
     ./vendor/bin/phpunit
+
+
+## Test
+
+### Infection
+
+* https://infection.github.io
+
+Install:
+
+    composer global require infection/infection
+
+or
+
+    brew install infection
+
+Run:
+
+    infection

infection.json.dist

@@ -0,0 +1,11 @@
+{
+    "timeout": 10,
+    "source": {
+        "directories": [
+            "src"
+        ]
+    },
+    "logs": {
+        "text": "build/infection-log.txt"
+    }
+}