fixed for github build

Author: hauner

build.gradle

@@ -23,8 +23,8 @@ ext {
     processorApiVersion = '1.1.0'
     jacksonVersion = '2.11.3'
 
-    bintrayUser = project.hasProperty ('BINTRAY_USER') ? BINTRAY_USER : 'n/a'
-    bintrayKey =  project.hasProperty ('BINTRAY_KEY')  ? BINTRAY_KEY  : 'n/a'
+    bintrayUser = project.findProperty ('BINTRAY_USER') ?: System.getenv ("BINTRAY_USER") ?: 'n/a'
+    bintrayKey =  project.findProperty ('BINTRAY_KEY') ?: System.getenv ("BINTRAY_KEY") ?: 'n/a'
 }