adding travis.yml

"make -debug" is not a thing. I meant "make --debug"

README -> README.md

added travis build status link and image to README.md

.travis.yml :
 * added sudo apt-get upgrade
 * removed sudo apt-get install libreadline-dev (travis already has it)

adding .gitignore

removing apt-get update, upgrade since it takes time and doesn't do much

adding softlink README -> README.md

minor formatting change on README.md

made README.md prettier

README.md : even better formatting

building in ./build dir, added stuff to .gitignore

travis.yml : re-adding sudo apt-get update, upgrade