set pubsub default capacity to 0

Refs #951

Jae: I don't know a good way to catch these errors in general, but
forcing pubsub's internal channel to have a capacity of 0 will reveal
bugs sooner, if the subscriber also has a 0 or small capacity ch to pull
from.

rpc/lib/server/handlers.go

@@ -17,7 +17,7 @@ import (
 	"github.com/gorilla/websocket"
 	"github.com/pkg/errors"
 
-	"github.com/tendermint/go-amino"
+	amino "github.com/tendermint/go-amino"
 	types "github.com/tendermint/tendermint/rpc/lib/types"
 	cmn "github.com/tendermint/tmlibs/common"
 	"github.com/tendermint/tmlibs/log"

rpc/lib/types/types.go

@@ -7,7 +7,9 @@ import (
 	"strings"
 
 	"github.com/pkg/errors"
-	"github.com/tendermint/go-amino"
+
+	amino "github.com/tendermint/go-amino"
+
 	tmpubsub "github.com/tendermint/tendermint/libs/pubsub"
 )
 

types/event_bus.go

@@ -9,7 +9,7 @@ import (
 	"github.com/tendermint/tmlibs/log"
 )
 
-const defaultCapacity = 1000
+const defaultCapacity = 0
 
 type EventBusSubscriber interface {
 	Subscribe(ctx context.Context, subscriber string, query tmpubsub.Query, out chan<- interface{}) error