more publish fixes (#33)

Author: davidliu

build.gradle

@@ -22,6 +22,11 @@ def getReleaseRepositoryUrl() {
             : "https://ossrh-staging-api.central.sonatype.com/service/local/"
 }
 
+def getSnapshotRepositoryUrl() {
+    return hasProperty('SNAPSHOT_REPOSITORY_URL') ? SNAPSHOT_REPOSITORY_URL
+            : "https://central.sonatype.com/repository/maven-snapshots/"
+}
+
 def getRepositoryUsername() {
     return hasProperty('nexusUsername') ? nexusUsername : ""
 }
@@ -35,6 +40,7 @@ nexusPublishing {
     repositories {
         maven {
             nexusUrl.set(uri(getReleaseRepositoryUrl()))
+            snapshotRepositoryUrl.set(uri(getSnapshotRepositoryUrl()))
             username = getRepositoryUsername()
             password = getRepositoryPassword()
             stagingProfileId = STAGING_PROFILE_ID