Add support for 4.4 on Evergreen (#328)

Author: Divjot Arora

.evergreen/config.yml

@@ -1248,6 +1248,10 @@ axes:
   - id: version
     display_name: MongoDB Version
     values:
+      - id: "4.4"
+        display_name: "4.4"
+        variables:
+          VERSION: "4.4"
       - id: "4.2"
         display_name: "4.2"
         variables:
@@ -1390,8 +1394,8 @@ buildvariants:
     tasks:
       - name: ".test !.enterprise-auth !.snappy !.zstd"
 
-  - matrix_name: "tests-42-lts-zlib-zstd-support"
-    matrix_spec: { version: ["4.2", "latest"], os-ssl-32: "*" }
+  - matrix_name: "tests-42-plus-zlib-zstd-support"
+    matrix_spec: { version: ["4.2", "4.4", "latest"], os-ssl-32: "*" }
     display_name: "${version} ${os-ssl-32}"
     tasks:
       - name: ".test !.enterprise-auth !.snappy"