AppVeyor: Enable beta and nightly

Signed-off-by: Mohammad AlSaleh <[email protected]>

Author: MoSal

appveyor.yml

@@ -8,14 +8,14 @@ environment:
       target: x86_64-pc-windows-msvc
     - channel: nightly
       target: i686-pc-windows-msvc
-  # - channel: stable
-  #   target: x86_64-pc-windows-msvc
-  # - channel: stable
-  #   target: i686-pc-windows-msvc
-  # - channel: beta
-  #   target: x86_64-pc-windows-msvc
-  # - channel: beta
-  #   target: i686-pc-windows-msvc
+    - channel: stable
+      target: x86_64-pc-windows-msvc
+    - channel: stable
+      target: i686-pc-windows-msvc
+    - channel: beta
+      target: x86_64-pc-windows-msvc
+    - channel: beta
+      target: i686-pc-windows-msvc
 
 install:
   - appveyor DownloadFile https://win.rustup.rs/ -FileName rustup-init.exe