Pinned jms/serializer to 1.7.1 (#336)

* Pinned jms/serializer to 1.7.1

* Checking to update jms/serializer to 1.8.0 ONLY on php 5.4 for travis-ci

* Added comment, and added graphviz for class diagrams in generated api docs

Author: Benjamin Wilson Friedman

.travis.yml

@@ -9,7 +9,10 @@ php:
 #  - nightly
 before_install:
   - nvm install 6.11
+  - sudo apt-get install graphviz
 install:
+  # fix for jms/serializer 1.7.1 not being able to run on 5.4
+  - if [[ ${TRAVIS_PHP_VERSION:0:3} == "5.4" ]]; then composer require jms/serializer; fi
   - composer install
   - npm install
 before_script:

composer.json

@@ -19,7 +19,8 @@
     "require-dev": {
         "phpunit/phpunit": "~4.0",
         "squizlabs/php_codesniffer": "^3.0.1",
-        "phpdocumentor/phpdocumentor": "~2.9"
+        "phpdocumentor/phpdocumentor": "~2.9",
+        "jms/serializer": "1.7.1"
     },
     "autoload": {
         "psr-4": {