1. add `assert(resolve(before) === after)` to check before and after in test of resolveURI.
the function `assertResolves(before: String, after: String)` have two params, it means we should check the before value whether equals the after value which we want.
e.g. the after value of Utils.resolveURI("hdfs:///root/spark.jar#app.jar").toString should be "hdfs:///root/spark.jar#app.jar" rather than "hdfs:/root/spark.jar#app.jar". we need `assert(resolve(before) === after)` to make it more safe.
2. identify the cases between resolveURI and resolveURIs.
3. delete duplicate cases and some small fix make this suit more clear.