Older versions of FireFox do not scan

[mapresto]

Describe the bug
Running Invoke-PowerStigScan with FireFox as a role may fail to find the install directory because the current version key does not exist.

Expected behavior
The key location for the install directory is dependent on version number. The current version key exists at the "HKLM:\Software\Mozilla\Mozilla Firefox" path in newer versions that could be used to predict the location of the needed key for the install directory. Older versions do not have this and requires additional logic to find the current version and install directory.

[mapresto]

Fix is added to 1.0.0.2. Errors will still occur if you move backwards on Firefox version. There is no catch to determine the path if a newer version is removed and an older version is installed in a new location. The firefox uninstaller does not clean up the registry keys of old installs