Updated pypy to 2.3.1 and added pypy3

Both are marked (unsupported, experimental).
fix for libmemcached & cedar-14
Update Readme.md
Update Readme.md
Merge pull request #162 from cclauss/patch-6

Updated pypy to 2.3.1 and added pypy3
do not fail if buildpack dir is readonly
a finder is required for requirements.txt including cmd line options like --find-links
add SH wrappers to Scrapy
support deprecated egg based deploys