Add coordinator wrapper (#1792)

* wip first pass at coordinator wrapper

* implement cancels, helper methods, and more unit tests

* pin typeorm version in pipeline

* prettier

* add export to 0x.js

* generate ZeroEx transaction using EIP712

* update Coordinator artifact

* change OrderError -> TypedDataError

packages/0x.js/src/index.ts

@@ -10,6 +10,9 @@ export {
 
 export {
     ContractWrappers,
+    CoordinatorWrapper,
+    CoordinatorServerCancellationResponse,
+    CoordinatorServerError,
     DutchAuctionWrapper,
     ERC20TokenWrapper,
     ERC721TokenWrapper,