Add backtrace.io to "Sponsors" section

readme.md

@@ -219,7 +219,7 @@ We also need need scenarios to distribute with the game, when the time comes. Fo
 
 Companies that kindly allow us to use their stuff:
 
-| DigitalOcean | JetBrains | AppVeyor | Travis-CI |
-|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| [![do_logo_vertical_blue svg](https://user-images.githubusercontent.com/550290/36508276-8b572f0e-175c-11e8-8622-9febbce756b2.png)](https://www.digitalocean.com/) | [![jetbrains](https://user-images.githubusercontent.com/550290/36413299-0e0985ea-161e-11e8-8a01-3ef523b5905b.png)](https://www.jetbrains.com/) | [![AppVeyor](https://user-images.githubusercontent.com/550290/36508339-be413216-175c-11e8-97d8-760ced0931e8.png)](https://www.appveyor.com/) | [![Travis](https://raw.githubusercontent.com/travis-ci/docs-travis-ci-com/4b14eeab25ce8ca9164e177bfb60782a8535a822/images/travis-mascot-200px.png)](https://travis-ci.org/) |
-| Hosting of various services | CLion and other products | MSVC CI | Linux + macOS CI |
+| [DigitalOcean](https://www.digitalocean.com/) | [JetBrains](https://www.jetbrains.com/) | [AppVeyor](https://www.appveyor.com/) | [Travis-CI](https://travis-ci.org/) | [Backtrace](https://backtrace.io/) |
+|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
+| [![do_logo_vertical_blue svg](https://user-images.githubusercontent.com/550290/36508276-8b572f0e-175c-11e8-8622-9febbce756b2.png)](https://www.digitalocean.com/) | [![jetbrains](https://user-images.githubusercontent.com/550290/36413299-0e0985ea-161e-11e8-8a01-3ef523b5905b.png)](https://www.jetbrains.com/) | [![AppVeyor](https://user-images.githubusercontent.com/550290/36508339-be413216-175c-11e8-97d8-760ced0931e8.png)](https://www.appveyor.com/) | [![Travis](https://raw.githubusercontent.com/travis-ci/docs-travis-ci-com/4b14eeab25ce8ca9164e177bfb60782a8535a822/images/travis-mascot-200px.png)](https://travis-ci.org/) | [![backtrace](https://user-images.githubusercontent.com/550290/47113259-d0647680-d258-11e8-97c3-1a2c6bde6d11.png)](https://backtrace.io/) |
+| Hosting of various services | CLion and other products | MSVC CI | Linux + macOS CI | Minidump uploads and inspection |