Re-enable Travis CI

Author: weslleyspereira

.travis_inactive.yml renamed to .travis.yml

@@ -1,5 +1,6 @@
 # LAPACK
 
+[![Build Status](https://travis-ci.org/Reference-LAPACK/lapack.svg?branch=master)](https://travis-ci.org/Reference-LAPACK/lapack)
 ![CMake](https://github.com/Reference-LAPACK/lapack/actions/workflows/cmake.yml/badge.svg)
 ![Makefile](https://github.com/Reference-LAPACK/lapack/actions/workflows/makefile.yml/badge.svg)
 [![Appveyor](https://ci.appveyor.com/api/projects/status/bh38iin398msrbtr?svg=true)](https://ci.appveyor.com/project/langou/lapack/)