[V3 Sentry] Allow toggling of Sentry logging (#1214)

* Refactor sentry to allow toggle

* Rename sentry module

* Protect sentry manager

* Fix tests

* Fix EOF newlines

* Add docstrings

redbot/core/sentry.py

@@ -0,0 +1,30 @@
+import logging
+from raven import Client
+from raven.handlers.logging import SentryHandler
+
+from redbot.core import __version__
+
+__all__ = ("SentryManager",)
+
+
+class SentryManager:
+    """Simple class to manage sentry logging for Red."""
+
+    def __init__(self, logger: logging.Logger):
+        self.client = Client(
+            dsn=("https://62402161d4cd4ef18f83b16f3e22a020:9310ef55a502442598203205a84da2bb@"
+                 "sentry.io/253983"),
+            release=__version__,
+            include_paths=['redbot'],
+            enable_breadcrumbs=False
+        )
+        self.handler = SentryHandler(self.client)
+        self.logger = logger
+
+    def enable(self):
+        """Enable error reporting for Sentry."""
+        self.logger.addHandler(self.handler)
+
+    def disable(self):
+        """Disable error reporting for Sentry."""
+        self.logger.removeHandler(self.handler)