Introduce coroutinesVersion

See gh-19975

Author: sdeleuze

build.gradle

@@ -29,6 +29,7 @@ ext {
 	}
 
 	aspectjVersion       = "1.9.2"
+	coroutinesVersion    = "1.1.1"
 	freemarkerVersion    = "2.3.28"
 	groovyVersion        = "2.5.6"
 	hsqldbVersion        = "2.4.1"

spring-webflux/spring-webflux.gradle

@@ -40,8 +40,8 @@ dependencies {
 	optional("org.jetbrains.kotlin:kotlin-reflect:${kotlinVersion}")
 	optional("org.jetbrains.kotlin:kotlin-stdlib:${kotlinVersion}")
 	optional("com.google.protobuf:protobuf-java-util:3.6.1")
-	optional("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.1.1")
-	optional("org.jetbrains.kotlinx:kotlinx-coroutines-reactor:1.1.1")
+	optional("org.jetbrains.kotlinx:kotlinx-coroutines-core:${coroutinesVersion}")
+	optional("org.jetbrains.kotlinx:kotlinx-coroutines-reactor:${coroutinesVersion}")
 	testCompile("javax.xml.bind:jaxb-api:2.3.1")
 	testCompile("com.fasterxml:aalto-xml:1.1.1")
 	testCompile("org.hibernate:hibernate-validator:6.0.15.Final")