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Raise exception when openssl_sign() call fails

Fixes: lcobucci#132

Merge branch 'feature/openssl-ecdsa-certificate-compatibility' into 3.2

Merge branch 'fix-ecc-signer' into 3.1

fix typo

Merge branch 'feature/header-config' into 3.1

Merge branch 'fix-typ-header' into 3.0

Changing Travis to just allow failures in HHVM-nightly and disabling …

…some environment services in Scrutinizer.

Adding type cast to ValidationData (fixes lcobucci#28)

Merge pull request lcobucci#26 from lcobucci/fix-token-parsing

Delegating payload generation to Builder and Parser