Issues with REG.5 json file

[cwilliams-ericsson]

WINNF.FT.C.REG.5 (CPI signed data) has several issues with the associated json file REG_SingleStep_CPI_Success_cbsd1.json. Presumably REG_SingleStep_CPI_Success_cbsd2.json used in WINNF.FT.C.REG.6 is also impacted (although I didn't test that one). Issues are as follows:

1. "CpiSignatureData" should be "cpiSignatureData" (lower-case C) -- check protocol spec
2. encodedSpiSignedData length must be much larger than 128 characters. Suggest using 1024 instead (look at registrationOptional.json in pull-request #59 )
3. digitalSignature length must be much larger than 128 characters. Suggest using 1024 (look at registrationOptional.json in pull-request #59 )
4. installationParam is a required object. In fact, installationParam are in the cpiSignatureData. There is some discussion as to whether installationParam are even allowed to be in the registration request when cpiSignatureData is present, but at the least it should be optional if cpiSignatureData is present, so it should be removed from required json file.

All issues above cause a valid registration message containing cpiSignatureData to fail.

[cwilliams-ericsson]

For example, the cpiSignature fields I generate have encodedCpiSignedData = 710 bytes, and digitalSignature = 683 bytes (using RS256 signature algorithm, ES256 yields much smaller signature).

[cwilliams-ericsson]

Fixed in pull-request #77