v0.6.1 release

- Fix possible conflict with generated code in user's variable names (#239)

- Update scalafmt 2.0.0 (#236)
- Update mutation-testing-elements, ... to 1.1.1 (#241)
- Update log4j-api, log4j-core, ... to 2.12.0 (#237)
- Update scalameta to 4.2.0 (#235)
- Add Stryker4s logo to readme
- Update sbt-scoverage to 1.6.0 (#231)

Author: Hugo van Rijswijk

README.md

@@ -29,7 +29,7 @@ Stryker4s is a mutation testing framework for Scala. It allows you to test your
 Stryker4s provides a sbt plugin for easy use within sbt projects. To install the plugin, add the following line to `plugins.sbt`:
 
 ```scala
-addSbtPlugin("io.stryker-mutator" % "sbt-stryker4s" % "0.6.0")
+addSbtPlugin("io.stryker-mutator" % "sbt-stryker4s" % "0.6.1")
 ```
 
 After adding the plugin, Stryker4s can be used by running `sbt stryker` in the root of your project.
@@ -50,7 +50,7 @@ The Maven plugin can be added as follows in `pom.xml` under `plugins`:
 <plugin>
     <groupId>io.stryker-mutator</groupId>
     <artifactId>stryker4s-maven-plugin</artifactId>
-    <version>0.6.0</version>
+    <version>0.6.1</version>
 </plugin>
 ```