fix(core): Fix EndPhase deltalog (#812)

A side effect of calling EndPhase() is an automatic call to EndTurn().

Both endPhase and endTurn log entries are added to deltalog.

When the user mouses over LogEntries in the Debug Panel,
the state is regenerated/reduced from the deltalogs.
EndPhase() *again* makes an automatic call to EndTurn(), and
then the endTurn in the deltalog is also called, resulting in
one-too-many calls to EndTurn().

This issue affects games using DEFAULT turn order and
causes playback fail when using the Debug:Log Panel.
This error is generated to the browser console:

   ERROR: disallowed move: MYMOVENAME

where MYMOVENAME is the name of the move that fails.

Appears to correct issue #810

Issue also reported:

* 2020-06-23 07:05 - https://gitter.im/boardgame-io/General?at=5ef1f017b8152d34845bace8

* 2020-07-08 02:16 - https://gitter.im/boardgame-io/General?at=5f05778fc7d15f7d0f7b1e01

src/core/flow.ts

@@ -438,7 +438,7 @@ export function Flow({
 
   function EndPhase(state: State, { arg, next, turn, automatic }: any): State {
     // End the turn first.
-    state = EndTurn(state, { turn, force: true });
+    state = EndTurn(state, { turn, force: true, automatic: true });
 
     let G = state.G;
     let ctx = state.ctx;