feat: add base and celo (#54)

* feat: add base

* feat: add base goerli

* feat: add celo

* fix: no slash

Author: banteg

brownie_safe.py

@@ -38,7 +38,10 @@ class EthereumNetworkBackport(Enum):
     ARBITRUM_ONE = 42161
     AURORA_MAINNET = 1313161554
     AVALANCHE_C_CHAIN = 43114
+    BASE = 8453
+    BASE_GOERLI = 84531
     BINANCE_SMART_CHAIN_MAINNET = 56
+    CELO = 42220
     ENERGY_WEB_CHAIN = 246
     GOERLI = 5
     MAINNET = 1
@@ -55,7 +58,10 @@ class TransactionServiceBackport(TransactionServiceApi):
         EthereumNetworkBackport.ARBITRUM_ONE: "https://safe-transaction-arbitrum.safe.global",
         EthereumNetworkBackport.AURORA_MAINNET: "https://safe-transaction-aurora.safe.global",
         EthereumNetworkBackport.AVALANCHE_C_CHAIN: "https://safe-transaction-avalanche.safe.global",
+        EthereumNetworkBackport.BASE: "https://safe-transaction-base.safe.global",
+        EthereumNetworkBackport.BASE_GOERLI: "https://safe-transaction-base-testnet.safe.global",
         EthereumNetworkBackport.BINANCE_SMART_CHAIN_MAINNET: "https://safe-transaction-bsc.safe.global",
+        EthereumNetworkBackport.CELO: "https://safe-transaction-celo.safe.global",
         EthereumNetworkBackport.ENERGY_WEB_CHAIN: "https://safe-transaction-ewc.safe.global",
         EthereumNetworkBackport.GOERLI: "https://safe-transaction-goerli.safe.global",
         EthereumNetworkBackport.MAINNET: "https://safe-transaction-mainnet.safe.global",