Update template engine to know of templates in folders.
Update template engine to know of templates in folders.

* Template name is no longer basename - extension, it's
  path relative to view directory + basename - extension

BucksCountyCouncil/verify-local-patterns,nhsbsa/ppc-prototype,timpaul/ur_panel_prototype,dwpdigitaltech/ejs-prototype,dwpdigitaltech/ejs-prototype,danblundell/verify-local-patterns,Demwunz/esif-prototype,glancyea/tagtest,rivalee/licensing-prototype,nhsalpha/nhs_prototype_kit,arminio/govuk_prototype_kit,quis/notify-public-research-prototype,joelanman/govuk_prototype_kit,mharrington/nhs_prototype_kit,timpaul/nhs_prototype_kit,mharrington/nhs_prototype_kit,timpaul/registers-hackday,rivalee/licensing-prototype,dwpdigitaltech/hrt-prototype,PurpleBooth/govuk_prototype_kit,chrishanes/pvb_prisoner_proto,abbott567/govuk_prototype_kit,st3v3nhunt/prototype-ers,antimega/performance-self-serve-prototype,UKHomeOffice/ReportTerroristMaterialPrototype,mharrington/nhs_prototype_kit,timpaul/govuk_transaction_prototype_kit,bencullimore/nhsers,joelanman/govuk_transaction_prototype_kit,nhsbsa/ppc-prototype,Demwunz/esif-prototype,tsmorgan/marx,tsmorgan/jsa-complaints,davedark/proto-timeline,benjeffreys/hmcts-idam-proto,bencullimore/nhsers,timpaul/registers-hackday,chrishanes/pvb_prisoner_proto,karlparton/my-govuk,rivalee/local-gov-links,antimega/performance-self-serve-prototype,OrcaTom/dwp_contentpatterns,dwp-rti-prototype/rti-ux-new-prototype,OrcaTom/dwp_contentpatterns,alphagov/govuk_prototype_kit,LandRegistry/dmp-prototype,LandRegistry/dmp-prototype,dwp-rti-prototype/rti-ux-new-prototype,alphagov/govuk_prototype_kit,arminio/govuk_prototype_kit,dwpdigitaltech/hrt-prototype,abbott567/govuk_prototype_kit,DilwoarH/GDS-Prototype-DM-SavedSearch,antimega/cites-prototype,nhsalpha/nhs_prototype_kit,kenmaddison-scc/verify-local-patterns,dwpdigitaltech/ejs-prototype,hannalaakso/accessible-timeout-warning,mikieet/sm-prototype,st3v3nhunt/prototype-ers,tsmorgan/marx,quis/notify-public-research-prototype,jamesarice/DPSS,gavinwye/govuk_prototype_kit,st3v3nhunt/prototype-ers,PurpleBooth/govuk_prototype_kit,davedark/proto-timeline,kenmaddison-scc/verify-local-patterns,hannalaakso/accessible-timeout-warning,glancyea/tagtest,nhsalpha/nhs_prototype_kit,mikieet/sm-3,BucksCountyCouncil/verify-local-patterns,jeremygillies-ea/data_returns_prototype,timpaul/nhs_prototype_kit,rivalee/local-gov-links,danblundell/verify-local-patterns,jamesarice/DPSS,antimega/cites-prototype,samwake/hoddat-cofc-caseworking,st3v3nhunt/prototype-ers,glancyea/tagtest,paulpod/invgov,OrcaTom/dwp_contentpatterns,companieshouse/ch-accounts-prototype,joelanman/govuk_prototype_kit,LandRegistry/dmp-prototype,timpaul/nh_prototype_kit,samwake/hoddat-cofc-caseworking,kenmaddison-scc/verify-local-patterns,dwpdigitaltech/hrt-prototype,timpaul/GOVUKCountrySelector,dwp-rti-prototype/rti-ux-new-prototype,paulpod/invgov,paulpod/invgov,DilwoarH/GDS-Prototype-DM-SavedSearch,bencullimore/nhsers,tsmorgan/jsa-complaints,gup-dwp/pip-prototype-v2,timpaul/ur_panel_prototype,UKHomeOffice/ReportTerroristMaterialPrototype,DilwoarH/GDS-Prototype-DM-SavedSearch,BucksCountyCouncil/verify-local-patterns,nhsbsa/ppc-prototype,gup-dwp/pip-prototype-v2,dwpdigitaltech/digital-debt,dwpdigitaltech/digital-debt,arminio/govuk_prototype_kit,joelanman/govuk_prototype_kit,Demwunz/esif-prototype,quis/notify-public-research-prototype,danblundell/verify-local-patterns,gup-dwp/pip-prototype-v2,timpaul/GOVUKCountrySelector,timpaul/govuk_transaction_prototype_kit,gavinwye/govuk_prototype_kit,tsmorgan/marx,karlparton/my-govuk,samwake/hoddat-cofc-caseworking,bencullimore/nhsers,dwpdigitaltech/digital-debt,chrishanes/pvb_prisoner_proto,benjeffreys/hmcts-idam-proto,benjeffreys/hmcts-idam-proto,nhsalpha/nhs_prototype_kit,alphagov/govuk_prototype_kit,hannalaakso/accessible-timeout-warning,karlparton/my-govuk,mikieet/sm-prototype,mikieet/sm-3,companieshouse/ch-accounts-prototype,jeremygillies-ea/data_returns_prototype,jeremygillies-ea/data_returns_prototype,joelanman/govuk_transaction_prototype_kit,timpaul/nh_prototype_kit,abbott567/govuk_prototype_kit,davedark/proto-timeline