Rearrange and rename application routes.

- move application routes to their own Flask blueprint
- squash application routes to be resource-specific
- reorganize application routes

tests/routes/applications/test_new.py

@@ -0,0 +1,21 @@
+from flask import url_for
+
+from tests.factories import PortfolioFactory
+
+
+def test_creating_application(client, user_session):
+    portfolio = PortfolioFactory.create()
+    user_session(portfolio.owner)
+    response = client.post(
+        url_for("applications.create", portfolio_id=portfolio.id),
+        data={
+            "name": "Test Application",
+            "description": "This is only a test",
+            "environment_names-0": "dev",
+            "environment_names-1": "staging",
+            "environment_names-2": "prod",
+        },
+    )
+    assert response.status_code == 302
+    assert len(portfolio.applications) == 1
+    assert len(portfolio.applications[0].environments) == 3