fixes in publication scripts

postssystem.exposed/maven.publish.gradle

@@ -16,6 +16,7 @@ publishing {
             from components.java
             artifact sourcesJar
             artifact javadocJar
+
             groupId "${project.group}"
             artifactId "${project.name}"
             version "${project.version}"

postssystem.exposed/publish.gradle

@@ -9,6 +9,7 @@ ext {
 bintray {
     user = project.hasProperty('BINTRAY_USER') ? project.property('BINTRAY_USER') : System.getenv('BINTRAY_USER')
     key = project.hasProperty('BINTRAY_KEY') ? project.property('BINTRAY_KEY') : System.getenv('BINTRAY_KEY')
+    publications = ["maven"]
     filesSpec {
         into "$projectBintrayDir"
         from("build/libs") {
@@ -23,6 +24,7 @@ bintray {
         name = "${project.name}"
         vcsUrl = "https://github.com/PostsSystem/PostsSystemCore"
         licenses = ["Apache-2.0"]
+        publications = [ MavenPublication ]
         version {
             name = "${project.version}"
             released = new Date()
@@ -35,14 +37,4 @@ bintray {
     }
 }
 
-bintrayUpload.doFirst {
-    publications = publishing.publications.collect {
-        if (it.name.contains('kotlinMultiplatform')) {
-            null
-        } else {
-            it.name
-        }
-    } - null
-}
-
 bintrayUpload.dependsOn publishToMavenLocal