chore: remove trailing whitespace (#272)

README.md

@@ -11,7 +11,7 @@ This project currently provides the following functionality:
 You may also be interested in two other projects built on top of GenStage:
 
   * [Flow](https://github.com/plataformatec/flow) for building computational flows using map-reduce, partitions, windows, and more that run concurrently. See the documentation for [Flow](https://hexdocs.pm/flow) or [José Valim's keynote at ElixirConf 2016](https://youtu.be/srtMWzyqdp8?t=244) introducing the main concepts behind GenStage and Flow
-  
+
   * [Broadway](https://github.com/plataformatec/broadway) for building concurrent and multi-stage data ingestion and data processing pipelines to consume events from Amazon SQS, RabbitMQ, and others. See [Broadway's documentation](https://hexdocs.pm/broadway) or [José Valim's introduction to Broadway](https://www.youtube.com/watch?v=ZOExnT1PYjs)
 
 ## Examples

lib/gen_stage.ex

@@ -516,7 +516,7 @@ defmodule GenStage do
   Both `:producer_consumer` and `:consumer` stages have been designed to do
   their work in the `c:handle_events/3` callback. This means that, after
   `c:handle_events/3` has been executed, both `:producer_consumer` and `:consumer`
-  stages will immediately send demand upstream and ask for more items. It is 
+  stages will immediately send demand upstream and ask for more items. It is
   assumed that events have been fully processed by `c:handle_events/3`.
 
   Such default behaviour makes `:producer_consumer` and `:consumer` stages