def check_signature(secret)
      digest = OpenSSL::Digest::SHA256.new
      expected = OpenSSL::HMAC.hexdigest(digest, secret, @body)
      if @signature == expected
        return true
      else
        Pusher.logger.warn "Received WebHook with invalid signature: got #{@signature}, expected #{expected}"
        return false
      end
    end
def check_signature(secret)
      digest = OpenSSL::Digest::SHA256.new
      expected = OpenSSL::HMAC.hexdigest(digest, secret, @body)
      if @signature == expected
        return true
      else
        Pusher.logger.warn "Received WebHook with invalid signature: got #{@signature}, expected #{expected}"
        return false
      end
    end
Checks signature against secret and returns boolean