Bump up version to v2.6.2

Signed-off-by: Hiroshi Hatake <hatake@clear-code.com>

Author: cosmo0920

fluent-plugin-grok-parser.gemspec

@@ -4,7 +4,7 @@ $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 
 Gem::Specification.new do |spec|
   spec.name          = "fluent-plugin-grok-parser"
-  spec.version       = "2.6.1"
+  spec.version       = "2.6.2"
   spec.authors       = ["kiyoto", "Kenji Okimoto"]
   spec.email         = ["kiyoto@treasure-data.com", "okimoto@clear-code.com"]
   spec.summary       = %q{Fluentd plugin to support Logstash-inspired Grok format for parsing logs}