Rename invalidateContractInstanceAsync to invalidateContractInstancesAsync

src/0x.ts

@@ -162,7 +162,7 @@ export class ZeroEx {
      */
     public async setProviderAsync(provider: Web3Provider) {
         this._web3Wrapper.setProvider(provider);
-        await this.exchange.invalidateContractInstanceAsync();
+        await this.exchange.invalidateContractInstancesAsync();
         this.tokenRegistry.invalidateContractInstance();
         this.token.invalidateContractInstances();
         this._proxyWrapper.invalidateContractInstance();

src/contract_wrappers/exchange_wrapper.ts

@@ -86,7 +86,7 @@ export class ExchangeWrapper extends ContractWrapper {
         this._exchangeLogEventEmitters = [];
         this._exchangeContractByAddress = {};
     }
-    public async invalidateContractInstanceAsync(): Promise<void> {
+    public async invalidateContractInstancesAsync(): Promise<void> {
         await this.stopWatchingAllEventsAsync();
         this._exchangeContractByAddress = {};
     }