message: don't generate temp directory randomnly
diff: @@ -4,7 +4,7 @@ const filenamifyUrl = require('filenamify-url');
  const { existsSync } = require('fs');
  const { join } = require('path');
  const { Clone, Cred, Merge } = require('nodegit');
  -const temp = require('temp');
  +const { tmpdir } = require('os');
  class GitLocalCache {
  constructor() {
  @@ -38,7 +38,7 @@ class GitLocalCache {
  if (!cacheDirectory) {
  if(!this.cacheDirectory) {
  - this.cacheDirectory = temp.path('git-local-cache');
  + this.cacheDirectory = join(tmpdir(), 'cardstack-git-local-cache');
  }
  if(!existsSync(this.cacheDirectory)) {
  