Bump rxjava from 2.2.12 to 2.2.13 (#1031)

Bumps [rxjava](https://github.com/ReactiveX/RxJava) from 2.2.12 to 2.2.13.
- [Release notes](https://github.com/ReactiveX/RxJava/releases)
- [Changelog](https://github.com/ReactiveX/RxJava/blob/v2.2.13/CHANGES.md)
- [Commits](ReactiveX/RxJava@v2.2.12...v2.2.13)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

elide-core/pom.xml

@@ -110,7 +110,7 @@
         <dependency>
             <groupId>io.reactivex.rxjava2</groupId>
             <artifactId>rxjava</artifactId>
-            <version>2.2.12</version>
+            <version>2.2.13</version>
         </dependency>
 
         <!-- JSR 303 Validation -->