Updated requirements

- PHP: require 5.6 as minimum supported version
- PHPUnit: bump to ^5.6
- Update travis to test 7.1, but remove 5.5 testing

Author: weierophinney

.travis.yml

@@ -23,16 +23,15 @@ env:
 
 matrix:
   include:
-    - php: 5.5
-      env:
-        - CS_CHECK=true
-        - EXECUTE_DOC_CHECK=true
     - php: 5.6
       env:
         - TEST_COVERAGE=true
         - DEPLOY_DOCS="$(if [[ $TRAVIS_BRANCH == 'master' && $TRAVIS_PULL_REQUEST == 'false' ]]; then echo -n 'true' ; else echo -n 'false' ; fi)"
         - PATH="$HOME/.local/bin:$PATH"
     - php: 7
+      env:
+        - CS_CHECK=true
+    - php: 7.1
     - php: hhvm 
   allow_failures:
     - php: hhvm

composer.json

@@ -29,10 +29,10 @@
         }
     },
     "require": {
-        "php": "^5.5 || ^7.0"
+        "php": "^5.6 || ^7.0"
     },
     "require-dev": {
-        "phpunit/PHPUnit": "~4.0",
+        "phpunit/PHPUnit": "^5.6",
         "athletic/athletic": "^0.1",
         "zendframework/zend-stdlib": "^2.7.3 || ^3.0",
         "container-interop/container-interop": "^1.1.0",