Added support for multiple API versions (#533)

* Added support for multiple API versions

Note that no changes were made to the api, the code was refactored to allow for new versions of the api to be created down the road.

Here's what this would look like:
+-- api/
    +-- v1/
        +-- __init__.py
        +-- resources.py
    +-- v1_1/
        +-- __init__.py
        +-- resources.py
    +-- v2/
        +-- __init__.py
        +-- resources.py
    +-- __init__.py
    +-- common.py

* reformatted using black

/Users/drthrash/PycharmProjects/ihatemoney/ihatemoney/api/v1/resources.py
reformatted /Users/drthrash/PycharmProjects/ihatemoney/ihatemoney/api/common.py
All done! ✨ 🍰 ✨

* Applying fix for unused import in init.py

https://stackoverflow.com/questions/31079047/python-pep8-class-in-init-imported-but-not-used

* Formatting changes recommended by black

All done! ✨ 🍰 ✨
1 file reformatted, 22 files left unchanged.

5 files changed, 43 insertions, 26 deletions

diff --git a/ihatemoney/api/__init__.py b/ihatemoney/api/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/ihatemoney/api/__init__.py
diff --git a/ihatemoney/api.py b/ihatemoney/api/common.py
index 67c6cc1..728d2a8 100644
--- a/ihatemoney/api.py
+++ b/ihatemoney/api/common.py
@@ -1,7 +1,6 @@
 # coding: utf8
-from flask import Blueprint, request, current_app
-from flask_restful import Resource, Api, abort
-from flask_cors import CORS
+from flask import request, current_app
+from flask_restful import Resource, abort
 from wtforms.fields.core import BooleanField
 
 from ihatemoney.models import db, Project, Person, Bill
@@ -10,11 +9,6 @@ from werkzeug.security import check_password_hash
 from functools import wraps
 
 
-api = Blueprint("api", __name__, url_prefix="/api")
-CORS(api)
-restful_api = Api(api)
-
-
 def need_auth(f):
     """Check the request for basic authentication for a given project.
 
@@ -195,19 +189,3 @@ class TokenHandler(Resource):
 
         token = project.generate_token()
         return {"token": token}, 200
-
-
-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")
-restful_api.add_resource(MembersHandler, "/projects/<string:project_id>/members")
-restful_api.add_resource(
-    ProjectStatsHandler, "/projects/<string:project_id>/statistics"
-)
-restful_api.add_resource(
-    MemberHandler, "/projects/<string:project_id>/members/<int:member_id>"
-)
-restful_api.add_resource(BillsHandler, "/projects/<string:project_id>/bills")
-restful_api.add_resource(
-    BillHandler, "/projects/<string:project_id>/bills/<int:bill_id>"
-)
diff --git a/ihatemoney/api/v1/__init__.py b/ihatemoney/api/v1/__init__.py
new file mode 100644
index 0000000..11afff7
--- /dev/null
+++ b/ihatemoney/api/v1/__init__.py
@@ -0,0 +1,5 @@
+from .resources import api
+
+__all__ = [
+    "api",
+]
diff --git a/ihatemoney/api/v1/resources.py b/ihatemoney/api/v1/resources.py
new file mode 100644
index 0000000..821ba2b
--- /dev/null
+++ b/ihatemoney/api/v1/resources.py
@@ -0,0 +1,34 @@
+# coding: utf8
+from flask import Blueprint
+from flask_restful import Api
+from flask_cors import CORS
+
+from ihatemoney.api.common import (
+    ProjectsHandler,
+    ProjectHandler,
+    TokenHandler,
+    MemberHandler,
+    ProjectStatsHandler,
+    MembersHandler,
+    BillHandler,
+    BillsHandler,
+)
+
+api = Blueprint("api", __name__, url_prefix="/api")
+CORS(api)
+restful_api = Api(api)
+
+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")
+restful_api.add_resource(MembersHandler, "/projects/<string:project_id>/members")
+restful_api.add_resource(
+    ProjectStatsHandler, "/projects/<string:project_id>/statistics"
+)
+restful_api.add_resource(
+    MemberHandler, "/projects/<string:project_id>/members/<int:member_id>"
+)
+restful_api.add_resource(BillsHandler, "/projects/<string:project_id>/bills")
+restful_api.add_resource(
+    BillHandler, "/projects/<string:project_id>/bills/<int:bill_id>"
+)
diff --git a/ihatemoney/run.py b/ihatemoney/run.py
index 6d1e032..161761c 100644
--- a/ihatemoney/run.py
+++ b/ihatemoney/run.py
@@ -8,7 +8,7 @@ from flask_mail import Mail
 from flask_migrate import Migrate, upgrade, stamp
 from werkzeug.middleware.proxy_fix import ProxyFix
 
-from ihatemoney.api import api
+from ihatemoney.api.v1 import api as apiv1
 from ihatemoney.models import db
 from ihatemoney.utils import (
     IhmJSONEncoder,
@@ -132,7 +132,7 @@ def create_app(
 
     validate_configuration(app)
     app.register_blueprint(web_interface)
-    app.register_blueprint(api)
+    app.register_blueprint(apiv1)
     app.register_error_handler(404, page_not_found)
 
     # Configure the a, root="main"pplication