Linting CRLF encoded files causes an empty line to be inserted between each line of code

New Issue Checklist

• Updated SwiftLint to the latest version
• I searched for existing GitHub issues

Issue Description

Linting CRLF encoded files causes an empty line to be inserted between each line of code

Complete output when running SwiftLint, including the stack trace and command used

$ swiftlint autocorrect

Environment

• SwiftLint version 0.21.0
• Installation method used Homebrew
• Paste your configuration file:

# comments_space: # From https://github.com/brandenr/swiftlintconfig
#   name: "Space After Comment"
#   regex: '(^ *//\w+)'
#   message: "There should be a space after //"
#   severity: error
#
# force_https: # From https://github.com/Twigz/Game
#   name: "Force HTTPS over HTTP"
#   regex: "((?i)http(?!s))"
#   match_kinds: string
#   message: "HTTPS should be favored over HTTP"
#   severity: warning
#
# double_space: # From https://github.com/IBM-Swift/Package-Builder
#   include: "*.swift"
#   name: "Double space"
#   regex: '([a-z,A-Z] \s+)'
#   message: "Double space between keywords"
#   match_kinds: keyword
#   severity: warning

disabled_rules: # rule identifiers to exclude from running
  #Errors
  - force_try
  - force_cast
  - line_length
  - file_length
  - type_body_length
  - function_body_length
  - identifier_name
  - cyclomatic_complexity
  - large_tuple
  #Warnings
  - trailing_comma # Keep this exclusion
  - empty_parentheses_with_trailing_closure
  - function_parameter_count
  - vertical_whitespace # This rule is confused by Runes it seems

opt_in_rules: # some rules are only opt-in
  # Find all the available rules by running:
  # swiftlint rules

included: # paths to include during linting. `--path` is ignored if present.

excluded: # paths to ignore during linting. Takes precedence over `included`.
  - Carthage
  - Pods
  - fastlane

#reporter: "xcode" # reporter type (xcode, json, csv, checkstyle)

• Are you using nested configurations? No
• Which Xcode version are you using (check xcode-select -p)? 8.3.3
• Do you have a sample example that shows the issue? No. Create any CRLF encoded swift file.

Start with the swiftlint autocorrect entry point and trace how CRLF-encoded Swift files are read and rewritten. Reproduce the issue with a CRLF-encoded file, then verify that autocorrection no longer inserts an empty line between each line of code.