Moved /streams/now -> /now

Response is now JSON object of the form:
```json
{
    "epoch_time": 1629572206
}
```

It is not authenticated.

backend/moonstream/api.py

@@ -2,6 +2,7 @@
 The Moonstream HTTP API
 """
 import logging
+import time
 
 from fastapi import FastAPI, Form
 from fastapi.middleware.cors import CORSMiddleware
@@ -39,6 +40,11 @@ async def version_handler() -> data.VersionResponse:
     return data.VersionResponse(version=MOONSTREAM_VERSION)
 
 
+@app.get("/now", tags=["time"])
+async def now_handler() -> int:
+    return data.NowResponse(epoch_time=int(time.time()))
+
+
 app.mount("/subscriptions", subscriptions_api)
 app.mount("/users", users_api)
 app.mount("/streams", streams_api)

backend/moonstream/data.py

@@ -52,6 +52,14 @@ class VersionResponse(BaseModel):
     version: str
 
 
+class NowResponse(BaseModel):
+    """
+    Schema for responses on /now endpoint
+    """
+
+    epoch_time: int
+
+
 class SubscriptionUpdate(BaseModel):
     update: Dict[str, Any]
     drop_keys: List[str] = Field(default_factory=list)

backend/moonstream/routes/streams.py

@@ -2,7 +2,6 @@
 The Moonstream subscriptions HTTP API
 """
 import logging
-import time
 from typing import Dict, List, Optional
 
 from bugout.data import BugoutResource
@@ -88,11 +87,6 @@ def get_user_subscriptions(token: str) -> Dict[str, List[BugoutResource]]:
     return user_subscriptions
 
 
-@app.get("/now", tags=["streams"])
-async def now_handler() -> int:
-    return int(time.time())
-
-
 @app.get("/", tags=["streams"], response_model=data.GetEventsResponse)
 async def stream_handler(
     request: Request,