Add php versions support (#46)

* Add php versions support

* Upgrade changes

* Move cover annotation to class level

Co-authored-by: Trayan Ivanov <trayan.ivanov@gmail.com>

Author: stanstst

.travis.yml

@@ -3,12 +3,9 @@ language: php
 sudo: false
 
 php:
-  - 5.3
-  - 5.4
-  - 5.5
-  - 5.6
-  - 7.0
   - 7.1
+  - 7.2
+  - 7.3
 
 env:
   - DEPS=normal

composer.json

@@ -10,12 +10,12 @@
         }
     ],
     "require" : {
-        "php": ">=5.3.2",
+        "php": "^7.1",
         "lib-curl": "*",
         "swiftmailer/swiftmailer": "^5.0"
     },
     "require-dev" : {
-        "phpunit/phpunit": ">=4.0,<6.0"
+        "phpunit/phpunit": "^7"
     },
     "autoload": {
         "psr-4": {"Openbuildings\\Postmark\\": "src/"}
@@ -30,7 +30,7 @@
     },
     "config": {
         "platform": {
-            "php": "5.4"
+            "php": "7.1.8"
         }
     }
 }