add Travis CI

.travis.yml

@@ -0,0 +1,15 @@
+language: c
+compiler:
+  - gcc
+
+script:
+  - make
+  - make test
+  - make mtest
+  - ./mtest/mtest 666666 | ./test > test.log
+  - head -n 5 test.log
+  - tail -n 2 test.log
+
+branches:
+  only:
+    - develop

README.md

@@ -1,3 +1,5 @@
+[![Build Status](https://travis-ci.org/fperrad/libtommath.png?branch=develop)](https://travis-ci.org/fperrad/libtommath)
+
 This is the git repository for [LibTomMath](http://www.libtom.org/), a free open source portable number theoretic multiple-precision integer (MPI) library written entirely in C.
 
 The `develop` branch contains the in-development version. Stable releases are tagged.