feat: adds graceful exit when epgap does not converge

When the time limit (tilim) is reached but the epgap has not reached its threshold, JaBbA would still spit out an output (which was usually garbage/uninterpretable). Now it gracefully exits with an error message, suggesting the user increase the tilim.

R/JaBbA.R

@@ -646,6 +646,11 @@ JaBbA = function(## Two required inputs
     	QCStats(inputDT=data.table(pair=name,inputdir=outdir),outdir=outdir)
     }
     setwd(cdir)
+    # exit with error if epgap did not converge
+    sol_epgap = jab$nodes$gr$epgap %>% unique 
+    if (sol_epgap > opt$epgap) {
+        stop(paste("JaBbA did not converge. Try increasing the tilim. Final epgap:", sol_epgap))
+    }
     return(jab)
 }