Check if every unit is a function

[paulocoghi]

Gracefully stop a flow when at least one unit inside it isn't a function, informing on console.

This helps solving scenarios when a unit is wrongly named inside a flow, previously leading to hard to debug errors.

Now Unitflow prints to the console the exact flow and unit when the later isn't a function.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (71640b4) 100.00% compared to head (8c87d44) 100.00%.

Additional details and impacted files

@@            Coverage Diff            @@
##            master       #24   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            1         1           
  Lines           57        59    +2     
  Branches        11        13    +2     
=========================================
+ Hits            57        59    +2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.