Downgrade coroutines back to 1.2.x because of incompatibility

Author: oliemansm

pom.xml

@@ -15,7 +15,7 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <java.version>1.8</java.version>
         <kotlin.version>1.3.70</kotlin.version>
-        <kotlin-coroutines.version>1.3.5</kotlin-coroutines.version>
+        <kotlin-coroutines.version>1.2.1</kotlin-coroutines.version>
         <jackson.version>2.10.3</jackson.version>
         <graphql-java.version>14.0</graphql-java.version>