Added bump targets

Rakefile

@@ -19,3 +19,24 @@ task "build" => "date_epoch"
 task "date_epoch" do
   ENV["SOURCE_DATE_EPOCH"] = IO.popen(%W[git -C #{__dir__} log -1 --format=%ct], &:read)
 end
+
+helper = Bundler::GemHelper.instance
+def helper.version=(v)
+  gemspec.version = v
+  tag_version
+end
+major, minor, teeny = helper.gemspec.version.segments
+
+task "bump:teeny" do
+  helper.version = Gem::Version.new("#{major}.#{minor}.#{teeny+1}")
+end
+
+task "bump:minor" do
+  helper.version = Gem::Version.new("#{major}.#{minor+1}.0")
+end
+
+task "bump:major" do
+  helper.version = Gem::Version.new("#{major+1}.0.0")
+end
+
+task "bump" => "bump:teeny"