Squashed bug causing incorrect digits. Now fully working

I totally brainfarted and put this->preDigits.size() in the for
loop comparison clause, which gets re-evaluated every loop.
So it was leaving digits on the stack that should have been
printed, causing errors both immediately and down the line.

main.cpp

@@ -1,9 +1,17 @@
 #include <iostream>
+#include <cstdlib>
 #include "Spigot.hpp"
 
-int main(void) {
-    Spigot *piSpigot = new Spigot(1000);
-    for(int i = 0; i < 1000; i++) {
+int main(int argc, char **argv) {
+    int numDigits = 0;
+    if(argc < 2) {
+        std::cout << "Usage: spigot <numDigits>" << std::endl;
+        return -1;
+    } else {
+        numDigits = std::atoi((const char *)argv[1]);
+    }
+    Spigot *piSpigot = new Spigot(numDigits);
+    for(int i = 0; i < numDigits; i++) {
         piSpigot->pump();
     }
     return 0;