Update dependency dockerfile_lint to version 0.2.7

[renovate-bot]

This Pull Request updates dependency dockerfile_lint from version 0.2.4 to 0.2.7

Changelog

0.2.7 / 2017-03-18

• 0.2.7
• fixing FROM rules array (#78)
  Fixes #77
• Merge branch 'master' of github.com:projectatomic/dockerfile_lint
• Fix -e option
• add escape character to hyphen in FROM line - fixes #70 (#72)
• regex must not be quoted, some text fixes (#73)
  • don't quote regex
    fix error messages
  • regex must not be quoted
  • minor fixes to osbs.yaml
    add modules.yaml to check module Dockerfiles
• fixing docker docs link (#74)

0.2.6 / 2017-01-29

• 0.2.6
• Remove stray debug statement

0.2.5 / 2017-01-23

• 0.2.5
• Maintainer rule (#65)
  • Removing MAINTAINER as required rule
  • Fix typo
• Remove FROM regitry rule (#64)
• Merge pull request #62 from lostintangent/patch-1
  Adding Docker 1.12 valid instructions
• Fixing typo
• Parsing healthcheck instructions
• Updating rules/tests
• Merge pull request #60 from dav1x/AddShellToLibParser
  Adds shell to libparser
• Merge pull request #61 from lphiri/master
  Fix typo and error handling
• Fixing tests
• Adding Docker 1.12 valid instructions
  This simply updates the valid instructions list in the base rules in order to support the `HEALTHCHECK` AND `SHELL` commands that were added in Docker 1.12.
• Merge remote-tracking branch 'upstream/master'
• Fix invalid command handling
• Merge pull request #58 from dav1x/fixportFROMline
  fixes 57 add support for port number in FROM line
• mend
• fixes 57 add support for port number in FROM line
• Merge pull request #56 from romain-dartigues/PR/56
  accept dot in FROM version and dash in USER
• accept dash in FROM and USER