Add initial Keybase Chat support (#877)

* initial work on native keybase bridging

* Hopefully make a functional keybase bridge

* add keybase to bridgemap

* send to right channel, try to figure out received msgs

* add account and userid

* i am a Dam Fool

* Fix formatting for messages, handle /me

* update vendors, ran golint and goimports

* move handlers to handlers.go, clean up unused config options

* add sample config, fix inconsistent remote nick handling

* Update readme with keybase links

* Resolve fixmie errors

* Error -> Errorf

* fix linting errors in go.mod and go.sum

* explicitly join channels, ignore messages from non-specified channels

* check that team names match before bridging message

vendor/github.com/keybase/go-keybase-chat-bot/kbchat/test_config.example.yaml

@@ -0,0 +1,16 @@
+# Rename this file to `test_config.yaml`
+
+config:
+  bots:
+    alice:
+      username: "alice"
+      paperkey: "foo bar car..."
+    bob:
+      username: "bob"
+      paperkey: "one two three four..."
+  teams:
+    acme:
+      # A real team that you add your alice1 and bob1 into
+      name: "acme"
+      # The channel to use
+      topicname: "mysupercoolchannel"