[#428] Make it easier to locate corrupt templates
Merge pull request #428 from okfn/428-template-corruption-help

Corrupt templates are hard to locate
Add WebTest==1.4.3 to our pip-requirements.txt

WebTest >= 2.0 requires WebOb>=1.2, but we have WebOb==1.0.8 in our
requirements.txt (and we need it), so we're stuck with an older WebTest
version.

Fixes #491.
[#491] Pin nose version on pip-requirements-test.txt
Merge branch 'master' into 493-schema-fix