Created evergreen directory

Author: rstam

evergreen.yml renamed to evergreen/evergreen.yml

@@ -2,13 +2,13 @@ tasks:
 - name: compile
   commands:
   - command: git.get_project
-    params: 
+    params:
       directory: mongo-csharp-driver
   - command: shell.exec
-    params: 
+    params:
       working_dir: mongo-csharp-driver
       script: |
-        powershell.exe .\\build.ps1 -target Build
+        powershell.exe .\\build.ps1 -target BuildNet45
 
 buildvariants:
 - name: windows-64-compile