Don't globally reconfigure BigNumber

Author: lookfirst

package.json

@@ -1,6 +1,6 @@
 {
   "name": "bittrex-typescript",
-  "version": "2.1.0",
+  "version": "2.1.1",
   "description": "Bittrex client using typescript",
   "main": "src/index.js",
   "types": "src/index.d.ts",

src/model/DataConverter.js

@@ -3,7 +3,7 @@ import BigNumber from 'bignumber.js';
 
 // Disable the error about 15 decimal places
 // Happens during Bittrex.marketSummaries()
-BigNumber.config({ERRORS: false});
+const BN = BigNumber.another({ERRORS: false});
 
 @JsonConverter
 export class DateConverter implements JsonCustomConvert<Date> {
@@ -19,10 +19,10 @@ export class DateConverter implements JsonCustomConvert<Date> {
 @JsonConverter
 export class BigNumberConverter implements JsonCustomConvert<BigNumber> {
 	serialize(big: BigNumber): any {
-		return big.toNumber();
+		return new BN(big).toNumber();
 	}
 
 	deserialize(big: any): BigNumber {
-		return big ? new BigNumber(big) : null;
+		return big ? new BN(big) : null;
 	}
 }