fix callx function to hide waiting gif if call failed

tutorial

Merge pull request #46 from leandrosardi/blackops

migrating devops to blackops library

https://github.com/MassProspecting/docs/issues/320

new version 1.7.0

https://github.com/MassProspecting/docs/issues/178

new version 1.6.8

new version 1.6.7

new version 1.6.6

new version 1.6.5