Adding ability to tell signing object to honor/ignore envelope version

Added an optional parameter 'sign_everything' to honor or ignore the doc_version envelope field.  Default will be to ignore, which is legacy support.
fix a bug with verification when public key is missing
increment version and update support for newer gnupg

Signed-off-by: Jim Klo <jim.klo@sri.com>
Merge branch 'master' of github.com:jimklo/LRSignature
Fixed install dependency for python-gnupg

python-gnupg 0.3.0 mysteriously disappeared from cheese shop.  so made dependency now >= 0.3.0.

Signed-off-by: Jim Klo <jim.klo@sri.com>
updated fetch utility and Verify with new features

key fetch utility can now scrape php public key blocks that have Windows line termination.

Verify has a new public function get_and_verify which returns verified signature data after successful validation.

Signed-off-by: Jim Klo <jim.klo@sri.com>
release 0.1.13

Signed-off-by: Jim Klo <jim.klo@sri.com>
updating tests to work with Jenkins CI
bug fixes

fix for improper coercion of nested envelope properties of type String,
fix to drop numeric objects from the canonical form to follow spec.

Signed-off-by: Jim Klo <jim.klo@sri.com>
modify signing to 'drop' numbers when they are the value of a map.

Dropping in this case means converting to null (None).  This retains the key but with an empty value.

Signed-off-by: Jim Klo <jim.klo@sri.com>