fix(sdk-coin-tao): prevent real api calls by using beforeEach for stubbing

TICKET: WIN-4315

Author: nvrakesh06

modules/sdk-coin-tao/test/unit/tao.ts

@@ -27,7 +27,7 @@ describe('Tao:', function () {
     let headerInfoCB;
     let getFeeCB;
 
-    before(function () {
+    beforeEach(function () {
       accountInfoCB = sandBox.stub(Tao.prototype, 'getAccountInfo' as keyof Tao);
       headerInfoCB = sandBox.stub(Tao.prototype, 'getHeaderInfo' as keyof Tao);
       getFeeCB = sandBox.stub(Tao.prototype, 'getFee' as keyof Tao);