Began implementing SRP
added SRP tests

also slightly refactored startLogin and finishLogin
Tweak .awsboxen.json to use new "UserDataFiles" helper function.
Pass in database password as a template parameter.
Merge pull request #43 from dannycoates/srp2

Implement SRP login
turn on hapi doc generation plugin
Use CloudFormation::Init metadata to write instance config files.
Add a load-balancer for IdP webheads
Update to latest awsboxen dependency
Merge pull request #45 from mozilla/hapi_docs

turn on hapi doc generation plugin
Merge pull request #44 from mozilla/rfk/awsboxen-tweaks

AWSBoxen deployment tweaks
Add descriptions to SRP routes and add response validation where missing
Merge pull request #46 from mozilla/more_docs

Add descriptions to SRP routes and add response validation where missing
implemented /sign with hawk credentials

uses the signToken to derive the hawk
tokenId and reqHMACkey as specified:
https://wiki.mozilla.org/Identity/AttachedServices/KeyServerProtocol#Signing_Certificates
removed extra JSON stringify/parse
added /sign tests with invalid data

the payload validation test will fail until hapi is fixed.
see https://github.com/spumko/hapi/pull/949
Merge pull request #47 from dannycoates/signCert

implemented /sign with hawk credentials