List supported currencies in API under api/currencies

docs/api.md

@@ -242,3 +242,23 @@ You can get some project stats with a `GET` on
             "balance": -10.5
         }
     ]
+
+### Currencies
+
+You can get a list of supported currencies with a `GET` on
+`/api/currencies`:
+
+    $ curl --basic https://ihatemoney.org/api/currencies
+    [
+        "XXX",
+        "AED",
+        "AFN",
+        .
+        .
+        .
+        "ZAR",
+        "ZMW",
+        "ZWL"
+    ]
+
+

ihatemoney/api/common.py

@@ -5,6 +5,7 @@ from flask_restful import Resource, abort
 from werkzeug.security import check_password_hash
 from wtforms.fields.core import BooleanField
 
+from ihatemoney.currency_convertor import CurrencyConverter
 from ihatemoney.emails import send_creation_email
 from ihatemoney.forms import EditProjectForm, MemberForm, ProjectForm, get_billform_for
 from ihatemoney.models import Bill, Person, Project, db
@@ -49,6 +50,13 @@ def need_auth(f):
     return wrapper
 
 
+class CurrenciesHandler(Resource):
+    currency_helper = CurrencyConverter()
+
+    def get(self):
+        return self.currency_helper.get_currencies()
+
+
 class ProjectsHandler(Resource):
     def post(self):
         form = ProjectForm(meta={"csrf": False})

ihatemoney/api/v1/resources.py

@@ -5,6 +5,7 @@ from flask_restful import Api
 from ihatemoney.api.common import (
     BillHandler,
     BillsHandler,
+    CurrenciesHandler,
     MemberHandler,
     MembersHandler,
     ProjectHandler,
@@ -17,6 +18,7 @@ api = Blueprint("api", __name__, url_prefix="/api")
 CORS(api)
 restful_api = Api(api)
 
+restful_api.add_resource(CurrenciesHandler, "/currencies")
 restful_api.add_resource(ProjectsHandler, "/projects")
 restful_api.add_resource(ProjectHandler, "/projects/<string:project_id>")
 restful_api.add_resource(TokenHandler, "/projects/<string:project_id>/token")