Fix indentation in keywords
Update Travis CI build to install gperf.
Merge pull request #1037 from carsonmcdonald/traviscigperf

Update Travis CI build to install gperf
Merge pull request #1036 from kano4/pr-fix-indentation-in-keywords

Fix indentation in keywords
update lex.def
remove gperf installation that is not needed if src/lex.def is properly updated; cancel #1037
bugfix escape charactor for Regexp class
Merge pull request #1038 from kouki-o-iij/pr-regexp-escape

bugfix escape charactor for Regexp class