[MINOR][BUILD] Download RAT and R version info over HTTPS; use RAT 0.12

## What changes were proposed in this pull request?

This is trivial, but bugged me. We should download software over HTTPS.
And we can use RAT 0.12 while at it to pick up bug fixes.

## How was this patch tested?

N/A

Author: Sean Owen <[email protected]>

Closes apache#18927 from srowen/Rat012.

Author: srowen

dev/appveyor-install-dependencies.ps1

@@ -26,7 +26,7 @@ Function InstallR {
   }
 
   $urlPath = ""
-  $latestVer = $(ConvertFrom-JSON $(Invoke-WebRequest http://rversions.r-pkg.org/r-release-win).Content).version
+  $latestVer = $(ConvertFrom-JSON $(Invoke-WebRequest https://rversions.r-pkg.org/r-release-win).Content).version
   If ($rVer -ne $latestVer) {
     $urlPath = ("old/" + $rVer + "/")
   }

dev/check-license

@@ -20,7 +20,7 @@
 
 acquire_rat_jar () {
 
-  URL="http://repo1.maven.org/maven2/org/apache/rat/apache-rat/${RAT_VERSION}/apache-rat-${RAT_VERSION}.jar"
+  URL="https://repo1.maven.org/maven2/org/apache/rat/apache-rat/${RAT_VERSION}/apache-rat-${RAT_VERSION}.jar"
 
   JAR="$rat_jar"
 
@@ -58,7 +58,7 @@ else
     declare java_cmd=java
 fi
 
-export RAT_VERSION=0.11
+export RAT_VERSION=0.12
 export rat_jar="$FWDIR"/lib/apache-rat-${RAT_VERSION}.jar
 mkdir -p "$FWDIR"/lib