Remove Travis CI configuration and badge (#28, thanks @striezel)

The tests are not running on Travis CI anymore, so there is no
point in keeping that stuff around.

[skip ci]

README.md

@@ -1,6 +1,6 @@
 # ring-span lite: A circular buffer view for C++98 and later
 
-[![Language](https://img.shields.io/badge/C%2B%2B-98/11/14/17-blue.svg)](https://en.wikipedia.org/wiki/C%2B%2B#Standardization)  [![License](https://img.shields.io/badge/license-BSL-blue.svg)](https://opensource.org/licenses/BSL-1.0) [![Build Status](https://github.com/martinmoene/ring-span-lite/actions/workflows/ci.yml/badge.svg)](https://github.com/martinmoene/ring-span-lite/actions/workflows/ci.yml) [![Build Status](https://travis-ci.com/martinmoene/ring-span-lite.svg?branch=master)](https://travis-ci.com/martinmoene/ring-span-lite) [![Build status](https://ci.appveyor.com/api/projects/status/w2dgn3fxyrd6vcq8?svg=true)](https://ci.appveyor.com/project/martinmoene/ring-span-lite) [![Version](https://badge.fury.io/gh/martinmoene%2Fring-span-lite.svg)](https://github.com/martinmoene/ring-span-lite/releases) [![download](https://img.shields.io/badge/latest-download-blue.svg)](https://github.com/raw/martinmoene/ring-span-lite/master/include/nonstd/ring_span.hpp) [![Conan](https://img.shields.io/badge/on-conan-blue.svg)](https://conan.io/center/ring-span-lite) [![Try it on wandbox](https://img.shields.io/badge/on-wandbox-blue.svg)](https://wandbox.org/permlink/GHo8T1PIo7TV7eoG) [![Try it on godbolt online](https://img.shields.io/badge/on-godbolt-blue.svg)](https://godbolt.org/z/7n4Byc)
+[![Language](https://img.shields.io/badge/C%2B%2B-98/11/14/17-blue.svg)](https://en.wikipedia.org/wiki/C%2B%2B#Standardization)  [![License](https://img.shields.io/badge/license-BSL-blue.svg)](https://opensource.org/licenses/BSL-1.0) [![Build Status](https://github.com/martinmoene/ring-span-lite/actions/workflows/ci.yml/badge.svg)](https://github.com/martinmoene/ring-span-lite/actions/workflows/ci.yml) [![Build status](https://ci.appveyor.com/api/projects/status/w2dgn3fxyrd6vcq8?svg=true)](https://ci.appveyor.com/project/martinmoene/ring-span-lite) [![Version](https://badge.fury.io/gh/martinmoene%2Fring-span-lite.svg)](https://github.com/martinmoene/ring-span-lite/releases) [![download](https://img.shields.io/badge/latest-download-blue.svg)](https://github.com/raw/martinmoene/ring-span-lite/master/include/nonstd/ring_span.hpp) [![Conan](https://img.shields.io/badge/on-conan-blue.svg)](https://conan.io/center/ring-span-lite) [![Try it on wandbox](https://img.shields.io/badge/on-wandbox-blue.svg)](https://wandbox.org/permlink/GHo8T1PIo7TV7eoG) [![Try it on godbolt online](https://img.shields.io/badge/on-godbolt-blue.svg)](https://godbolt.org/z/7n4Byc)
 
 **Contents**
 

project/CodeBlocks/ring-span-lite.cbp

@@ -13,7 +13,6 @@
 		</Build>
 		<Unit filename="../../.gitattributes" />
 		<Unit filename="../../.gitignore" />
-		<Unit filename="../../.travis.yml" />
 		<Unit filename="../../CHANGES.txt" />
 		<Unit filename="../../CMakeLists.txt" />
 		<Unit filename="../../LICENSE.txt" />