adjust Makefile to accomodate packaging change

- get kindlegen from subfolder
- add test
fix test to work under bundler
reeanble the build task when running the tests
add build as prerequisite task for test
Merge pull request #8 from mojavelinux/kindlegen-extract-fix

adjust Makefile to accomodate packaging change
tabify
erase all ENVs for against shellshock vulnerability
bump version
support tachikoma.io
use instance methods of ENV to manipulate it
use Open3.capture3 instead of systemu
support windows
update tarball path
support new zip style

* new zip file is not have all files under subdirectory
bump version
fixed testing error on ruby 2.1.5