Merge pull request #129 from Edugate/develop

cleaning
Merge branch 'develop' into 1.x-stable
Merge branch 'develop' into 1.x-stable
Merge branch 'develop' into 1.x-stable
Merge pull request #130 from Edugate/develop

metadata validation
Merge branch 'develop' into 1.x-stable
Merge branch 'develop' into 1.x-stable
add time execution for for sync