## What changes were proposed in this pull request?
It seems Hadoop libraries need winutils binaries for native libraries in the path.
It is not a problem in tests for now because we are only testing SparkR on Windows via AppVeyor but it can be a problem if we run Scala tests via AppVeyor as below:
```
- SPARK-18220: read Hive orc table with varchar column *** FAILED *** (3 seconds, 937 milliseconds)
org.apache.spark.sql.execution.QueryExecutionException: FAILED: Execution Error, return code -101 from org.apache.hadoop.hive.ql.exec.mr.MapRedTask. org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)Z
at org.apache.spark.sql.hive.client.HiveClientImpl$$anonfun$runHive$1.apply(HiveClientImpl.scala:625)
at org.apache.spark.sql.hive.client.HiveClientImpl$$anonfun$runHive$1.apply(HiveClientImpl.scala:609)
at org.apache.spark.sql.hive.client.HiveClientImpl$$anonfun$withHiveState$1.apply(HiveClientImpl.scala:283)
...
```
This PR proposes to add it to the `Path` for AppVeyor tests.
## How was this patch tested?
Manually via AppVeyor.
**Before**
https://ci.appveyor.com/project/spark-test/spark/build/549-windows-complete/job/gc8a1pjua2bc4i8m
**After**
https://ci.appveyor.com/project/spark-test/spark/build/572-windows-complete/job/c4vrysr5uvj2hgu7
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#16584 from HyukjinKwon/set-path-appveyor.