Update to Omnipay 3, purchases 0.11, shipping 0.13, PHP 7.1+

Author: hkdobrev

.travis.yml

@@ -3,8 +3,9 @@ language: php
 sudo: false
 
 php:
-  - 7.0
   - 7.1
+  - 7.2
+  - 7.3
 
 matrix:
   fast_finish: true

composer.json

@@ -18,11 +18,11 @@
 		}
 	],
 	"require": {
-		"php": "^7",
+		"php": "^7.1",
 		"composer/installers": "*",
 		"openbuildings/jam": "^0.5",
-		"openbuildings/purchases": "^0.9 | ^0.10",
-		"openbuildings/shipping": "^0.10 | ^0.11",
+		"openbuildings/purchases": "^0.11",
+		"openbuildings/shipping": "^0.13",
 		"openbuildings/jam-monetary": "^0.1.21"
 	},
 	"require-dev": {