Generic approach to CI execution

[betabandido]

We currently use running_on_jenkins? to determine whether the execution is part of a continuous integration process. This is certainly not very generic.

For AWS infrastructures, for instance, one of the differences when running on jenkins is that the shared credentials file does not typically exist on the jenkins server. Instead, a key and secret are used. On development machines, using the profile information stored in the shared credentials file is the preferred option as it is more flexible.

It would be desirable to find a more generic approach to solve this requirement.