Setup MS PYLS automatically.

[seagle0128]

Close #33.

Get the lastest version of MS PYLS from the Microsoft website, and download to the specified path,
then setup to lsp automatically. Additional setup is not necessary. It's out of box.

[yyoncho]

Looks good! Few minor comments which may or may not be addressed as part of this PR.

[yyoncho]

We may consider asking the user to manually unzip the file in case there is no powershell on this PC

[seagle0128]

The powershell is built-in since Windows 7. And the behavior is same as dap-mode (dap-utils.el).

[yyoncho]

Then it seems to be ok to rely on that, thank you.

[smallzhan]

Nice work! A minor issue is that, on windows system, when mspyls is in use, (lsp-pyton-ms-update-server) may fail because of the mspyls directory can't be deleted ("Permission denied"), it will only success when mypyls is not started or killed by hand. That is a question only in windows system, i.e. if a file is used by some process, the directory containing that file can't be renamed or deleted...

If keep the updated server in a new directory, there must be a file to keep track the latest version, make the extension more complicated... So, maybe some instructions in source file is a good choice.

[seagle0128]

@smallzhan Good point! But it's not necessary to handle this scenario. I will add doc strings later.

[seagle0128]

@yyoncho I think it's fine to merge now.

[twlz0ne]

I think async-shell-command is better than shell-command.

Also, is there a curl in powershell?

[yyoncho]

I think async-shell-command is better than shell-comman

In general yes, but lsp-mode is expecting the command to finish synchronously. Until this is fixed we might introduce an interactive async version of the installation command.

Also, is there a curl in powershell?

AFAIK no.

[cireu]

Windows 10 contains a limited curl, but hard to use (I means it can't work well with request). @twlz0ne @yyoncho

[MikusR]

Windows 10 contains a limited curl, but hard to use (I means it can't work well with request). @twlz0ne @yyoncho

Windows 10 1903 has full curl 7.55.1. When called from powershell you have to use curl.exe as simply curl is an alias to Invoke-WebRequest.