Bump logback-classic from 1.1.7 to 1.2.0

Bumps logback-classic from 1.1.7 to 1.2.0.

---
updated-dependencies:
- dependency-name: ch.qos.logback:logback-classic
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -90,7 +90,7 @@
     <slf4j.version>1.7.5</slf4j.version>
     <netty.version>4.0.30.Final</netty.version>
     <log4j.version>2.7</log4j.version>
-    <logback.version>1.1.7</logback.version>
+    <logback.version>1.2.0</logback.version>
     <commons.version>3.1</commons.version>
     <junit.version>4.11</junit.version>
     <commons-httpclient.version>3.1</commons-httpclient.version>