Detect miniconda in different locations

[faph]

Currently the macros only detect previous miniconda3 installations in %LOCALAPPDATA%\Continuum\Miniconda3. Users may have previously manually installed it in a different location. Typical locations include:

• %LOCALAPPDATA%\Continuum\Miniconda3
• %PROFILE%\Miniconda3
• C:\Miniconda3

There's also the miniconda (Python 2.x) version.

Not sure what the best way to find the install location. Possibly the uninstall key in the registry like this: HKCU\Software\Microsoft\Windows\CurrentVersion\Uninstall\Python 3.4.3 (Miniconda3 3.16.0 64-bit) and then use the UninstallString value. Reg key will be in HKLM for system-wide installs.

The key name doesn't seem to be too robust to detect though.

Alternatively just search for Scripts\conda.exe?