Test against the latest stable sqlsrv extension

.appveyor.yml

@@ -68,8 +68,8 @@ install:
           Add-Content php.ini "`n extension=php_curl.dll"
           Add-Content php.ini "`n curl.cainfo=C:\tools\cacert\bundle.pem"
 
-          # Get and install the MSSQL DLL's
-          $DLLVersion = "5.2.0"
+          # Get and install the latest stable sqlsrv DLL's
+          $DLLVersion = (Invoke-WebRequest "https://pecl.php.net/rest/r/sqlsrv/stable.txt").Content
           cd c:\tools\php\ext
           $source = "https://windows.php.net/downloads/pecl/releases/sqlsrv/$($DLLVersion)/php_sqlsrv-$($DLLVersion)-$($env:php)-nts-vc15-x64.zip"
           $destination = "c:\tools\php\ext\php_sqlsrv-$($DLLVersion)-$($env:php)-nts-vc15-x64.zip"

tests/travis/install-mssql-pdo_sqlsrv.sh

@@ -3,4 +3,4 @@
 set -ex
 
 echo "Installing extension"
-pecl install pdo_sqlsrv-5.2.0
+pecl install pdo_sqlsrv

tests/travis/install-mssql-sqlsrv.sh

@@ -3,4 +3,4 @@
 set -ex
 
 echo "Installing extension"
-pecl install sqlsrv-5.2.0
+pecl install sqlsrv