feat(testnet): enable osmosis grpc (#128)

<!-- < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < ☺
v                               ✰  Thanks for creating a PR! ✰
v    Before smashing the submit button please review the checkboxes.
v If a checkbox is n/a - please still include it but + a little note why
☺ > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >  -->

## Overview

This PR updates the `local-osmosis-testnet-continue.sh` script to start
the Osmosis node with the gRPC endpoint enabled.

closes: #XXXX

## What changes have been made in this PR?

- [ ]

## Checklist

---

- [ ] Appropriate labels applied
- [ ] Targeted PR against correct branch
- [ ] Linked to Github issue with discussion and accepted design OR link
to spec that describes this work.
- [ ] Wrote unit and integration
- [ ] Updated relevant documentation

Makefile

@@ -26,7 +26,4 @@ optimize:
 
 initlocal: optimize _initlocal
 _initlocal:
-	bash scripts/testnet/init_stake_contract.sh
-migratelocal: optimize _migratelocal
-_migratelocal:
-	bash scripts/testnet/migrate_stake_contract.sh
+	bash scripts/testnet/init-stake-contract.sh

scripts/testnet/Local-Testnet.md

@@ -38,7 +38,7 @@ Before deploying the contracts, you need to:
 After completing the above steps, you can deploy the contracts by running:
 
 ```sh
-./init_stake_contract.sh
+./init-stake-contract.sh
 ```
 
 This script will initialize all the contracts and print out their addresses.

scripts/testnet/local-osmosis-testnet-continue.sh

@@ -10,4 +10,7 @@ set -e
 killall osmosisd || true
 
 # start all three validators
-tmux new -s osmosis1 -d osmosisd start --home="$HOME"/.osmosisd/validator1 --rpc.laddr tcp://0.0.0.0:26657
+tmux new -s osmosis1 -d osmosisd start --home="$HOME"/.osmosisd/validator1 \
+  --grpc.enable \
+  --rpc.laddr tcp://0.0.0.0:26657 \
+  --grpc.address 0.0.0.0:9090 \