Fix linting errors

Author: Jeff Ammons

docs/example-plugins/canary.py

@@ -9,4 +9,5 @@ def canary():
     # NOTE: you must add a real channel ID for this to work
     outputs.append(["D12345678", "bot started: " + str(time.time())])
 
+
 canary()

rtmbot/__init__.py

@@ -1 +1 @@
-from .core import *
+from .core import *  # noqa: F403, F401

rtmbot/bin/run_rtmbot.py

@@ -32,5 +32,6 @@ def main(args=None):
     except KeyboardInterrupt:
         sys.exit(0)
 
+
 if __name__ == "__main__":
     main()