Update coursier to 2.1.0-M5 (#180)

Author: alexarchambault

src/main.ts

@@ -4,7 +4,7 @@ import * as os from 'os'
 import * as path from 'path'
 import * as tc from '@actions/tool-cache'
 
-const csVersion = '2.1.0-M3'
+const csVersion = '2.1.0-M5'
 const coursierVersionSpec = csVersion
 
 async function execOutput(cmd: string, ...args: string[]): Promise<string> {