[tests] Get TS tests working on Windows with cross-env

[Alanscut]

Changes

• Import cross env, Fix errors reported by ts3.1-typescript-test and typescript test running on windows
• Working well on windows and Mac.

[coveralls]

Coverage remained the same at 88.485% when pulling 93e49c5 on Alanscut:issue_command into 4d0f390 on moment:develop.

[marwahaha]

@Alanscut Why do the typing tests fail on Windows?
I would prefer not to add an additional library, even as a devDep, but I also notice you are really contributing to this library. Thank you for that! If this is something you need for you to be a developer, let's add it.

[Alanscut]

@marwahaha As far as windows developer are concerned, it is necessary, otherwise executing npm run test will give an error.

Error information

node_modules\typescript\bin\tsc" is not recognized as an internal or external command, operable program or batch file
https://stackoverflow.com/questions/43430760/unable-to-compile-typescript#
https://stackoverflow.com/questions/37585966/node-modules-bin-package-cmd-file-in-node-js/44468968#44468968

New solutions

Add nyc to the command line, but I have not verified it on mac, what do you think?

"ts3.1-typescript-test": "nyc --reporter=none node_modules/typescript3/bin/tsc --project ts3.1-typing-tests",
"typescript-test": "nyc --reporter=none node_modules/typescript/bin/tsc --project typing-tests",

[marwahaha]

I'm ok with cross-env !
Please resolve the conflicts and we can include this.

[Alanscut]

@marwahaha Conflict resolved, thanks 😄 .