negative unallocated students message is confusing

[alexholcombe]

Line 289 of studentAllocation.vue, below, yields a very confusing message when there are more spaces (say, 10) than there are students (say, 2). Then because ${minUnallocated} == -2, the user will get a message saying "At least -2 students will be unallocated." Easy to fix - sorry I didn't do it but I didn't manage to get the repo to compile from source on my machine (can't remember which library I had trouble with).

   this.log([`***** Total effective cap is ${this.totalCap} spaces for students. At least ${minUnallocated} students will be unallocated`])