Use modern 7.3 TDSVER default for modern FreeTDS

I am the author of Ruby's TinyTDS and ActiveRecord SQL Server stack. I work close with the FreeTDS team too. The 0.95 version bring long awaited support to 2008 and upward data types like [datetime2]. These types are only usable under the TDSVER of 7.3 and upward. Changing the default does not stop others from using it, but it does modern expectations for data types that have been out since 2008.

Closes #504.

Signed-off-by: Andrew Janke <andrew@apjanke.net>

Formula/freetds.rb

@@ -38,7 +38,7 @@ class Freetds < Formula
   def install
     args = %W[
       --prefix=#{prefix}
-      --with-tdsver=7.1
+      --with-tdsver=7.3
       --mandir=#{man}
     ]