unloading error still occurs

[rubenarslan]

#113 seems to still be a problem. When I update a package via devtools that depends on e.g. knitr, I get the following anytime I try to use knitr via the opencpu API:

Error in value[3L]: Package 'knitr' version 1.19 cannot be unloaded:

The fix I linked at the bottom still works, but I had hoped you could prevent the problem from occurring.