Fix repository links (#200)

- Fix/Update repository links in README.md and gemspec
- Removed AppVeyor build status badges that are not working

Author: kojix2

README.md

@@ -5,8 +5,7 @@
 
 # PyCall: Calling Python functions from the Ruby language
 
-[![Build Status](https://github.com/mrkn/pycall.rb/workflows/CI/badge.svg)](https://github.com/mrkn/pycall.rb/actions?query=workflow%3ACI)
-[![Build status](https://ci.appveyor.com/api/projects/status/0fad23u4qj1yr49e/branch/master?svg=true)](https://ci.appveyor.com/project/mrkn/pycall-rb/branch/master)
+[![Build Status](https://github.com/red-data-tools/pycall.rb/workflows/CI/badge.svg)](https://github.com/red-data-tools/pycall.rb/actions?query=workflow%3ACI)
 
 This library provides the features to directly call and partially interoperate
 with Python from the Ruby language.  You can import arbitrary Python modules
@@ -228,7 +227,7 @@ version, push git commits and tags, and push the `.gem` file to
 ## Contributing
 
 Bug reports and pull requests are welcome on GitHub at
-https://github.com/mrkn/pycall.rb.
+https://github.com/red-data-tools/pycall.rb.
 
 
 ## Acknowledgement

pycall.gemspec

@@ -17,7 +17,7 @@ Gem::Specification.new do |spec|
 
   spec.summary       = %q{pycall}
   spec.description   = %q{pycall}
-  spec.homepage      = "https://github.com/mrkn/pycall"
+  spec.homepage      = "https://github.com/red-data-tools/pycall.rb"
   spec.license       = "MIT"
 
   spec.files         = `git ls-files -z`.split("\x0").reject do |f|