SecretKey KeyGen function using ciphersuiteID instead of api_id

[roblesjoel]

In the generate secret key function (see here) only the cyphersuiteID is used for the key_dst.
Instead the api_id needs to be used.

So in the definition of key_dst it should be:

Defaults to the octet string ciphersuite_id || "H2G_HM2S_" || "KEYGEN_DST_" if not supplied

[roblesjoel]

Additional Information:
The Error comes from the keypair.json fixture in the SHA folder.
If "H2G_HM2S_" is not included the test fails as it produces a different secret key.
When using api_id || "KEYGEN_DST_" the secret key is correct.