Enhancement: Collect coverage on Travis CI

.travis.yml

@@ -2,16 +2,18 @@ language: php
 
 dist: precise
 
-php:
-    - 5.3
-    - 5.4
-    - 5.5
-    - 5.6
-    - 7.0
-    - 7.1
-    - 7.2
-    - 7.3
-    - nightly
+jobs:
+  include:
+    - php: 5.3
+    - php: 5.4
+    - php: 5.5
+    - php: 5.6
+    - php: 7.0
+    - php: 7.1
+    - php: 7.2
+    - php: 7.3
+      env: WITH_COVERAGE=true
+    - php: nightly
 
 matrix:
     allow_failures:
@@ -22,9 +24,13 @@ cache:
     - $HOME/.composer/cache
 
 before_install:
-  - phpenv config-rm xdebug.ini || true
+  - source .travis/xdebug.sh
+  - xdebug-disable
 
 before_script:
-    - travis_retry composer install --no-interaction --prefer-dist
+  - travis_retry composer install --no-interaction --prefer-dist
 
-script: make sniff test
+script:
+  - make sniff
+  - if [[ "$WITH_COVERAGE" == "true" ]]; then xdebug-enable; fi
+  - if [[ "$WITH_COVERAGE" == "true" ]]; then make coverage; else make test; fi

.travis/xdebug.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+# The problem is that we do not want to remove the configuration file, just disable it for a few tasks, then enable it
+#
+# For reference, see
+#
+# - https://docs.travis-ci.com/user/languages/php#Disabling-preinstalled-PHP-extensions
+# - https://docs.travis-ci.com/user/languages/php#Custom-PHP-configuration
+
+config="/home/travis/.phpenv/versions/$(phpenv version-name)/etc/conf.d/xdebug.ini"
+
+function xdebug-disable() {
+    if [[ -f $config ]]; then
+        mv $config "$config.bak"
+    fi
+}
+
+function xdebug-enable() {
+    if [[ -f "$config.bak" ]]; then
+        mv "$config.bak" $config
+    fi
+}

readme.md

@@ -1,5 +1,7 @@
 # Faker
 
+[![Code Coverage](https://codecov.io/gh/fzaninotto/Faker/branch/master/graph/badge.svg)](https://codecov.io/gh/fzaninotto/Faker)
+
 Faker is a PHP library that generates fake data for you. Whether you need to bootstrap your database, create good-looking XML documents, fill-in your persistence to stress test it, or anonymize data taken from a production service, Faker is for you.
 
 Faker is heavily inspired by Perl's [Data::Faker](http://search.cpan.org/~jasonk/Data-Faker-0.07/), and by ruby's [Faker](https://rubygems.org/gems/faker).
@@ -53,7 +55,7 @@ composer require fzaninotto/faker
 
 ### Autoloading
 
-Faker supports both `PSR-0` as `PSR-4` autoloaders. 
+Faker supports both `PSR-0` as `PSR-4` autoloaders.
 ```php
 <?php
 # When installed via composer