getdeps: add manifests for pexpect and python-ptyprocess

Summary:
Add a manifest to download pexpect-4.7.0 from PyPI, as well as its ptyprocess
dependency.

Reviewed By: wez

Differential Revision: D17669618

fbshipit-source-id: 13395ec07f503f39adb3dc5aa8d0c2d8d0f1d927

build/fbcode_builder/manifests/pexpect

+[manifest]
+name = pexpect
+
+[download]
+url = https://files.pythonhosted.org/packages/0e/3e/377007e3f36ec42f1b84ec322ee12141a9e10d808312e5738f52f80a232c/pexpect-4.7.0-py2.py3-none-any.whl
+sha256 = 2094eefdfcf37a1fdbfb9aa090862c1a4878e5c7e0e7e7088bdb511c558e5cd1
+
+[build]
+builder = python-wheel
+
+[dependencies]
+python-ptyprocess

build/fbcode_builder/manifests/python-ptyprocess

+[manifest]
+name = python-ptyprocess
+
+[download]
+url = https://files.pythonhosted.org/packages/d1/29/605c2cc68a9992d18dada28206eeada56ea4bd07a239669da41674648b6f/ptyprocess-0.6.0-py2.py3-none-any.whl
+sha256 = d7cc528d76e76342423ca640335bd3633420dc1366f258cb31d05e865ef5ca1f
+
+[build]
+builder = python-wheel