* Need implementation of an openSSL based ECDSA signing using NIST P256v1 #255

* Restyled by clang-format

* Fix crypto test in Travis CI

* PR Feedback. Add a new test to test signing using SHA256

* PR Feedback - use SHA256. Limit to P56v1 curve. change API to let caller pass in the signature buffer

* Update min signature buffer size

* Update msg signature buffer length.

* Update msg signature buffer length.

* Delete unused method

* Update comments

* Rename kMinimum_ECDSA_Signature_Buffer_Length to kMax_ECDSA_Signature_Length

* Update API comments

Co-authored-by: Bhaskar Sarma <bhaskars@apple.com>
Co-authored-by: Restyled.io <commits@restyled.io>