add initial Travis CI configuration

.travis.yml

+language: cpp
+
+compiler:
+  - gcc
+  - clang
+
+before_install:
+  - echo $LANG
+  - echo $LC_ALL
+  - if [ $TRAVIS_OS_NAME == linux ]; then sudo apt-get update && sudo apt-get install -y g++ libgnutls-dev; fi
+  - if [ $TRAVIS_OS_NAME == osx ]; then brew update && brew install llvm36 && brew install gnutls && brew link --force llvm36; fi
+
+before_script:
+  - travis_retry bundle
+  - if [ $TRAVIS_OS_NAME == linux ]; then travis_retry ./autogen.sh && ./configure; fi
+  - if [ $TRAVIS_OS_NAME == osx ]; then travis_retry ./autogen.sh && ./configure; fi
+
+script: make -j
+
+notifications:
+  email:
+      - adrien.beraud@savoirfairelinux.com
+
+env:
+  - LANG="en_US.UTF-8"
+
+os:
+  - linux
+  - osx