Fix LZMAFile.seek on Python 2

In Python 2, builtins.open returns file objects which don't have the 'seekable' attribute. io.open is the Python 3 style interface to file.open.
unit test
Thank Tomer for seekable fix (will go into v0.0.2)
Fix typo in keywords metadata
add more search paths for the lzma headers/lib
Thank Wynn as a contributor (more header paths)
Fix readme's revision markup for GitHub display
Bump version to v0.0.2
cffi version
remove travis.yml
Revert "remove travis.yml"

This reverts commit 694f9449e807e9f245d1e49e59a3f727ce4211f7.
travis -- install cffi
removed print statements
remove more Python 3-incompatible things
README
restore 2.6 compatibility (hopefully)
indenting
requirements.txt
typo
complete test coverage