new condition class

[mvalkobi]

Resolves #67 #80 #81

Broke out the condition statement

1. trial now runs a loop over the condition list as it takes an argument
2. Timer no longer tasks the condition list
3. Condition list is now an object. All searching over via loops is removed and so does the add_condition function. No longer is needed and can be done by the constructor.
   This will make testing new conditions much more simple going forward.

Documentation is not finalized and will be post review of design.

[saumil-sh]

The pkgdown ci is failing due to pak. I cannot reproduce this locally.

[mvalkobi]

Approved