Test coverals (#279)

Changed coveralls to codecov

.coveralls.yml

-coverage_clover: coverage.clover
-service_name: travis-ci
-json_path: ./coveralls.json
-repo_token: N0kfaH0FRNy0iRNjUsqerRDLcPsuMBNOZ
\ No newline at end of file

.gitignore

 /vendor/
 /phpunit.xml
 /composer.lock
+coverage.xml
\ No newline at end of file

.travis.yml

@@ -6,7 +6,7 @@ php:
   - 7.2
 env:
   global:
-    - ES_VERSION=6.5.4 ES_DOWNLOAD_URL=https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-${ES_VERSION}.tar.gz
+    - ES_VERSION=6.7.1 ES_DOWNLOAD_URL=https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-${ES_VERSION}.tar.gz
 install:
   - wget ${ES_DOWNLOAD_URL}
   - tar -xzf elasticsearch-${ES_VERSION}.tar.gz
@@ -16,7 +16,7 @@ before_script:
   - composer install --no-interaction --prefer-dist
 script:
   - wget -q --waitretry=1 --retry-connrefused -T 10 -O - http://127.0.0.1:9200
-  - vendor/bin/phpunit --coverage-clover=coverage.clover
+  - vendor/bin/phpunit --coverage-clover=coverage.xml
   - vendor/bin/phpcs -p --standard=PSR2 --ignore=vendor/ ./
 after_script:
-  - travis_retry php vendor/bin/php-coveralls
\ No newline at end of file
+  - travis_retry bash <(curl -s https://codecov.io/bash)
\ No newline at end of file

README.md

@@ -6,6 +6,7 @@ If you need any help, [stack overflow](http://stackoverflow.com/questions/tagged
 is the preffered and recommended way to ask ONGR support questions.
  
 [![Build Status](https://travis-ci.org/ongr-io/ElasticsearchDSL.svg?branch=master)](https://travis-ci.org/ongr-io/ElasticsearchDSL)
+[![codecov](https://codecov.io/gh/ongr-io/ElasticsearchDSL/branch/master/graph/badge.svg)](https://codecov.io/gh/ongr-io/ElasticsearchDSL)
 [![Coverage Status](https://coveralls.io/repos/ongr-io/ElasticsearchDSL/badge.svg?branch=master&service=github)](https://coveralls.io/github/ongr-io/ElasticsearchDSL?branch=master)
 [![Latest Stable Version](https://poser.pugx.org/ongr/elasticsearch-dsl/v/stable)](https://packagist.org/packages/ongr/elasticsearch-dsl)
 [![Total Downloads](https://poser.pugx.org/ongr/elasticsearch-dsl/downloads)](https://packagist.org/packages/ongr/elasticsearch-dsl)

phpunit.xml.dist

@@ -32,9 +32,7 @@
             </exclude>
         </whitelist>
     </filter>
-
     <logging>
         <log type="coverage-text" target="php://stdout" showOnlySummary="true"/>
     </logging>
-
 </phpunit>