go: fix DoRandomSearch unit test

the test was previously failing due to a folder not present when results
were to be saved.

algo/algo_test.go

@@ -4,6 +4,7 @@
 package algo
 
 import (
+	"os"
 	"sync"
 	"testing"
 )
@@ -11,13 +12,15 @@ import (
 var wg sync.WaitGroup
 
 func TestDoRandomSearchExec(t *testing.T) {
-	// TODO(me): figure out how to test this.
+	wg.Add(1)
 
-	// wg.Add(1)
+	go DoRandomSearch(&wg)
 
-	// go DoRandomSearch(&wg)
+	wg.Wait()
 
-	// wg.Wait()
+	if err := os.RemoveAll(picPath); err != nil {
+		t.Error(err)
+	}
 }
 
 func TestDoSHCExec(t *testing.T) {

algo/plot.go

@@ -59,6 +59,10 @@ func plotAllDims(allStats []stats.Stats, fPrefix, fExt string) {
 				log.Fatal(err)
 			}
 
+			if err := createFolder(picPath); err != nil {
+				log.Println(err)
+			}
+
 			filename := picPath +
 				fPrefix + "-" +
 				sanitiseFName(s.Algo) + "-" +