Support Rtools44 + use Rtools42 for R 4.2.x

pak's R 4.2.x build does not work, and I suspect
it is because of using Rtools40 instead of
Rtools42.

NEWS.md

@@ -1,4 +1,8 @@
 
+# rig 0.6.1 (prerelease)
+
+* rig now supports Rtools44 on Windows.
+
 # rig 0.6.0
 
 * rig now supports RPM based distros, in addition to Deboan and Ubuntu (#28).

src/windows.rs

@@ -150,12 +150,22 @@ fn add_rtools(version: String) -> Result<(), Box<dyn Error>> {
     }
     let client = &reqwest::Client::new();
     for ver in vers {
+	let rtools44 = &ver[0..2] == "44";
 	let rtools43 = &ver[0..2] == "43";
         let rtools42 = &ver[0..2] == "42";
         let rtools4 = &ver[0..1] == "4";
         let filename: String;
         let url: String;
-	if rtools43 {
+	if rtools44 {
+	    let rt44=Path::new("C:\\Rtools44");
+	    if rt44.exists() {
+		info!("Rtools44 is already installed");
+		continue;
+	    }
+	    filename = "rtools44.exe".to_string();
+            url = "https://github.com/r-hub/rtools44/releases/download/latest/rtools44.exe"
+                .to_string();
+	} else if rtools43 {
 	    let rt43=Path::new("C:\\Rtools43");
 	    if rt43.exists() {
 		info!("Rtools43 is already installed");
@@ -279,17 +289,29 @@ fn get_rtools_needed(version: Option<Vec<String>>) -> Result<Vec<String>, Box<dy
         let ver: String = String::from_utf8(out.stdout)?;
         let v35 = "35".to_string();
         let v40 = "40".to_string();
+	let v42 = "42".to_string();
 	let v43 = "43".to_string();
+	let v44 = "44".to_string();
+	let sv440 = semver::Version::parse("4.4.0")?;
 	let sv430 = semver::Version::parse("4.3.0")?;
+	let sv420 = semver::Version::parse("4.2.0")?;
 	let sv = semver::Version::parse(&ver)?;
         if &ver[0..1] == "3" {
             if !res.contains(&v35) {
                 res.push(v35);
             }
+	} else if sv >= sv440 {
+	    if !res.contains(&v44) {
+		res.push(v44)
+	    }
 	} else if sv >= sv430 {
 	    if !res.contains(&v43) {
 		res.push(v43)
 	    }
+	} else if sv >= sv420 {
+	    if !res.contains(&v42) {
+		res.push(v42)
+	    }
         } else if &ver[0..1] == "4" {
             if !res.contains(&v40) {
                 res.push(v40);