fix: Pin httplib2<0.31.0 instead of pyparsing

fix: Pin httplib2<0.31.0 instead of pyparsing

httplib2 0.31.0+ requires pyparsing>=3.0.4, creating a conflict
with our previous pyparsing<3.2.0 pin. This caused pip to install
pyparsing 2.4.7 which is too old for httplib2 0.31.1.

Pin httplib2<0.31.0 instead, which works with pyparsing<3.2.0 and
avoids the set_name/setName API compatibility issue.

Supersedes previous commit 259a817.

Change-Id: Ifd87911715cd2c44d934f58e92f7a2bf2f6d9ec0
Signed-off-by: Anil Belur <abelur@linuxfoundation.org>