Revert "Set springBootVersion to 2.4.0-RC1"

This reverts commit 43b44a1.

Author: jgrandja

gradle.properties

@@ -1,5 +1,5 @@
 version=0.0.3-SNAPSHOT
-springBootVersion=2.4.0-RC1
+springBootVersion=2.4.0-M3
 org.gradle.jvmargs=-Xmx3g -XX:MaxPermSize=2048m -XX:+HeapDumpOnOutOfMemoryError
 org.gradle.parallel=true
 org.gradle.caching=true