add chain-id flag

without it basecoin fails with

```
ERROR: BroadcastTxCommit got non-zero exit code: BaseInvalidSignature. ; Error in CheckTx;in validateInputsAdvanced();Error (base) invalid signature;SignBytes: 010C636861696E2D745448346D690100000000000000000104636F696E000000000000000001010114A677E98456071E3240EF0A2E0B80FFE7D36515BF010101066D79636F696E000000000000000501010001793B7E33EF94132E16534CC9BA59F74944065FA917A98DB68ABA806D219A452901010114E2AFEA4A193E85A2DBB8668D4EA0DC0B1A6AD63A010101066D79636F696E0000000000000005
```

mintnet-kubernetes/examples/basecoin/README.md

@@ -31,7 +31,7 @@ make create
 4. send 5 coins to it from the first pod
 
    ```
-   kubectl exec -c app tm-0 -- basecoin tx send --to "0x$ADDR" --amount 5mycoin --from /app/key.json
+   kubectl exec -c app tm-0 -- basecoin tx send --to "0x$ADDR" --amount 5mycoin --from /app/key.json --chain_id chain-tTH4mi
    ```