Revert "Moving to 2.15.0-SNAPSHOT on master branch."

This reverts commit 6d218777a7bef0679128db2fec5ec257987f0890.

Should only have been on master.
diff --git a/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy b/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy
index 5aa1bdc..7a62ae2 100644
--- a/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy
+++ b/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy
@@ -314,7 +314,7 @@
 
     // Automatically use the official release version if we are performing a release
     // otherwise append '-SNAPSHOT'
-    project.version = '2.15.0'
+    project.version = '2.14.0'
     if (!isRelease(project)) {
       project.version += '-SNAPSHOT'
     }
diff --git a/gradle.properties b/gradle.properties
index 299a616..f0ed4b41 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -23,4 +23,4 @@
 signing.gnupg.executable=gpg
 signing.gnupg.useLegacyGpg=true
 
-version=2.15.0-SNAPSHOT
+version=2.14.0-SNAPSHOT