Update to 2.2.8, bundler 1.15.4, rubygems 2.6.13

Author: docker-library-bot

2.2/alpine3.4/Dockerfile

@@ -8,8 +8,8 @@ RUN mkdir -p /usr/local/etc \
 	} >> /usr/local/etc/gemrc
 
 ENV RUBY_MAJOR 2.2
-ENV RUBY_VERSION 2.2.7
-ENV RUBY_DOWNLOAD_SHA256 234c8aee6543da9efd67008e6e7ee740d41ed57a52e797f65043c3b5ec3bcb53
+ENV RUBY_VERSION 2.2.8
+ENV RUBY_DOWNLOAD_SHA256 37eafc15037396c26870f6a6c5bcd0658d14b46cd5e191a3b56d89dd22d561b0
 ENV RUBYGEMS_VERSION 2.6.13
 
 # some of ruby's build scripts are written in ruby

2.2/jessie/Dockerfile

@@ -8,8 +8,8 @@ RUN mkdir -p /usr/local/etc \
 	} >> /usr/local/etc/gemrc
 
 ENV RUBY_MAJOR 2.2
-ENV RUBY_VERSION 2.2.7
-ENV RUBY_DOWNLOAD_SHA256 234c8aee6543da9efd67008e6e7ee740d41ed57a52e797f65043c3b5ec3bcb53
+ENV RUBY_VERSION 2.2.8
+ENV RUBY_DOWNLOAD_SHA256 37eafc15037396c26870f6a6c5bcd0658d14b46cd5e191a3b56d89dd22d561b0
 ENV RUBYGEMS_VERSION 2.6.13
 
 # some of ruby's build scripts are written in ruby

2.2/jessie/slim/Dockerfile

@@ -20,8 +20,8 @@ RUN mkdir -p /usr/local/etc \
 	} >> /usr/local/etc/gemrc
 
 ENV RUBY_MAJOR 2.2
-ENV RUBY_VERSION 2.2.7
-ENV RUBY_DOWNLOAD_SHA256 234c8aee6543da9efd67008e6e7ee740d41ed57a52e797f65043c3b5ec3bcb53
+ENV RUBY_VERSION 2.2.8
+ENV RUBY_DOWNLOAD_SHA256 37eafc15037396c26870f6a6c5bcd0658d14b46cd5e191a3b56d89dd22d561b0
 ENV RUBYGEMS_VERSION 2.6.13
 
 # some of ruby's build scripts are written in ruby