Add http as a dependency

Author: f3ath

pubspec.yaml

@@ -3,9 +3,10 @@ description: "JSON:API v1.0 (http://jsonapi.org) HTTP Client"
 homepage: "https://github.com/f3ath/json-api-dart"
 name: "json_api"
 version: "0.0.1-dev1"
-dev_dependencies:
+dependencies:
   http: "^0.12.0"
   json_api_document: "^0.3.8"
+dev_dependencies:
   pubspec_version: "^0.1.0"
   test: "1.3.0"
 environment: