Fixes Issue Where 'validate' CLI can only validate md5 and sha1

[nodanaonlyzuul]

Currently - the validate cli does some pre-flight checking that will falsely return "not a valid bag" if the manifest is something other than md5 or sha1.

The Bag class does a good job of validating, and logging any errors already.
I did a version bump since the output could be different and I want to be upfront that
if anyone is shelling out to bagit validate then the output could be different.

Here's a few example runs:

Against A Perfect sha512 manifested bag

$ bagit validate ~/Desktop/gigantic_bag

I, [2016-12-14T15:10:35.226085 #87202]  INFO -- : true

Against A Bag with corrupted files

$ bagit validate ~/Desktop/gigantic_bag

E, [2016-12-14T15:24:12.065865 #88549] ERROR -- : false: Consistency expected /Users/sschor/Desktop/gigantic_bag/data/lorem_1.txt to have Digest::SHA512: x969d110708b17873e9e6ca7ee4aef8baabbec765df80af88b9d6ec11711810bf6ce460610fbe4694c5a7f5808c284e8cacee9d3e12bf9bc4f76ec1329e5e45d, actual is 2969d110708b17873e9e6ca7ee4aef8baabbec765df80af88b9d6ec11711810bf6ce460610fbe4694c5a7f5808c284e8cacee9d3e12bf9bc4f76ec1329e5e45d, Consistency expected /Users/sschor/Desktop/gigantic_bag/data/video_1.mov to have Digest::SHA512: x0d70bc663de5afda6b1e95634115b8e81a63acbccb58a3530e5ad92fc0d25c2dc0b3d77c9009813c15d11453b17cea93980e8a8a3a64681a33f48706bbb56f1, actual is f0d70bc663de5afda6b1e95634115b8e81a63acbccb58a3530e5ad92fc0d25c2dc0b3d77c9009813c15d11453b17cea93980e8a8a3a64681a33f48706bbb56f1, Consistency expected /Users/sschor/Desktop/gigantic_bag/data/urand.data to have Digest::SHA512: x4f857fe404d2858140edfe74f1a45d93604e4884494b4a9d9c4851ba7dd11b1814020de8c2f169fd01d3dfcc57bd422e75794b5cc69236e75c42c84e7f7c911, actual is 64f857fe404d2858140edfe74f1a45d93604e4884494b4a9d9c4851ba7dd11b1814020de8c2f169fd01d3dfcc57bd422e75794b5cc69236e75c42c84e7f7c911, Consistency expected /Users/sschor/Desktop/gigantic_bag/manifest-sha512.txt to have Digest::SHA512: aa4d37c0708df182485ba7cc97732e24e898ee166aa73f79e2cb44232c7b55858852dd83a34322db02b9e8c05571f8de819dd39775f72062bf21e20891075ea3, actual is 234ba48d097666b1c56f2061a38908007f5354d3377dfd0edb2cec50698716972ffd34ee01553dcb8ab6ffe6331bc1d308388efb11d660bcc8ff9a20898e6c81, Consistency is invalid

With a manifest named 'manifest-sha51333.txt'

$ bagit validate ~/Desktop/gigantic_bag
/Users/sschor/.rvm/gems/ruby-2.3.0/gems/bagit-0.3.5/lib/bagit/valid.rb:65:in `block in consistent?': Algorithm sha51333 is not supported. (ArgumentError)
	from /Users/sschor/.rvm/gems/ruby-2.3.0/gems/bagit-0.3.5/lib/bagit/valid.rb:49:in `each'
...SNIP!

[coveralls]

Coverage remained the same at 98.361% when pulling 47df949 on nodanaonlyzuul:change-cli-output into f0593db on tipr:master.

[coveralls]

Coverage remained the same at 98.361% when pulling b62d02b on nodanaonlyzuul:change-cli-output into f0593db on tipr:master.