Build all 3.4.x versions

Author: hsbt

Dockerfile

@@ -103,7 +103,7 @@ COPY versions/3.3* /all-ruby/versions/
 RUN rake -j ${j} all-3.3
 
 COPY versions/3.4* /all-ruby/versions/
-RUN rake -j ${j} 3.4.0-preview1 3.4.0-preview2 3.4.0-rc1
+RUN rake -j ${j} all-3.4
 
 COPY lib/* /all-ruby/lib/
 COPY all-ruby /all-ruby/