Update hashdiff requirement from ~> 0.3.7 to ~> 1.0.0 (#874)

Updates the requirements on [hashdiff](https://github.com/liufengyun/hashdiff) to permit the latest version.
- [Release notes](https://github.com/liufengyun/hashdiff/releases)
- [Changelog](https://github.com/liufengyun/hashdiff/blob/master/changelog.md)
- [Commits](liufengyun/hashdiff@v0.3.7...v1.0.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Author: dependabot-preview[bot]

appium_lib.gemspec

@@ -20,7 +20,7 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency 'appium_thor', '~> 1.1', '>= 1.1.4'
   s.add_development_dependency 'fakefs', '~> 0.13.0'
-  s.add_development_dependency 'hashdiff', '~> 0.3.7'
+  s.add_development_dependency 'hashdiff', '~> 1.0.0'
   s.add_development_dependency 'posix-spawn', '~> 0.3'
   s.add_development_dependency 'pry'
   s.add_development_dependency 'rake', '~> 13.0'