fbcode_builder: build folly using cmake

Summary:
Update the fbcode_builder spec for folly to build folly using its newer CMake
build scripts, rather than autoconf.

Reviewed By: yfeldblum

Differential Revision: D6793682

fbshipit-source-id: b724cf8be4a1afe20bd96e6113395a4fd44c438a

build/fbcode_builder/specs/folly.py

@@ -8,6 +8,6 @@ from __future__ import unicode_literals
 def fbcode_builder_spec(builder):
     return {
         'steps': [
-            builder.fb_github_autoconf_install('folly/folly'),
+            builder.fb_github_cmake_install('folly/folly'),
         ],
     }