Gracefully report parser error when file not gherkin. Closes #35.
Gracefully report parser error when file not gherkin. Closes #35.

Squashed commit of the following:

commit 2e8f128abfbbd3091427cd3d8fa0a4de9f99b8b8
Author: Aslak Hellesøy <aslak.hellesoy@gmail.com>
Date:   Wed May 6 22:26:24 2015 +0200

    Simplify and unify how we deal with bad feature files

commit 7c3091b1e39532f87ba01845fdf41b14f0fa3ec2
Author: Steve Tooke <steve@boxjump.co.uk>
Date:   Wed Apr 29 12:40:05 2015 +0100

    Raise ParserError for empty/non-gherkin files in JavaScript

commit 174eb3b0afcf3bcb1aef38dd8e68b8bc32a0de5b
Author: Steve Tooke <steve@boxjump.co.uk>
Date:   Wed Apr 29 11:57:50 2015 +0100

    We now don't blow up if there is no Gherkin

commit db9ac4c045804c44536bc578be32a6955056037f
Author: Steve Tooke <steve@boxjump.co.uk>
Date:   Wed Apr 29 11:34:44 2015 +0100

    Add acceptance tests for attempting to parse empty/non-gherkin files.

thetutlage/gherkin3,araines/gherkin3,dg-ratiodata/gherkin3,amaniak/gherkin3,SabotageAndi/gherkin,vincent-psarga/gherkin3,hayd/gherkin3,SabotageAndi/gherkin,concertman/gherkin3,dg-ratiodata/gherkin3,vincent-psarga/gherkin3,thetutlage/gherkin3,vincent-psarga/gherkin3,dirkrombauts/gherkin3,pjlsergeant/gherkin,hayd/gherkin3,dg-ratiodata/gherkin3,thiblahute/gherkin3,concertman/gherkin3,pjlsergeant/gherkin,thiblahute/gherkin3,amaniak/gherkin3,dg-ratiodata/gherkin3,SabotageAndi/gherkin,curzona/gherkin3,dirkrombauts/gherkin3,vincent-psarga/gherkin3,chebizarro/gherkin3,cucumber/gherkin3,araines/gherkin3,dirkrombauts/gherkin3,SabotageAndi/gherkin,curzona/gherkin3,thetutlage/gherkin3,Zearin/gherkin3,cucumber/gherkin3,cucumber/gherkin3,thiblahute/gherkin3,hayd/gherkin3,moreirap/gherkin3,moreirap/gherkin3,concertman/gherkin3,vincent-psarga/gherkin3,hayd/gherkin3,araines/gherkin3,curzona/gherkin3,amaniak/gherkin3,Zearin/gherkin3,chebizarro/gherkin3,cucumber/gherkin3,moreirap/gherkin3,moreirap/gherkin3,moreirap/gherkin3,curzona/gherkin3,Zearin/gherkin3,pjlsergeant/gherkin,moreirap/gherkin3,pjlsergeant/gherkin,thiblahute/gherkin3,dg-ratiodata/gherkin3,araines/gherkin3,SabotageAndi/gherkin,araines/gherkin3,dg-ratiodata/gherkin3,Zearin/gherkin3,vincent-psarga/gherkin3,concertman/gherkin3,SabotageAndi/gherkin,curzona/gherkin3,thetutlage/gherkin3,araines/gherkin3,araines/gherkin3,amaniak/gherkin3,cucumber/gherkin3,chebizarro/gherkin3,Zearin/gherkin3,hayd/gherkin3,hayd/gherkin3,dg-ratiodata/gherkin3,amaniak/gherkin3,curzona/gherkin3,thetutlage/gherkin3,curzona/gherkin3,concertman/gherkin3,dirkrombauts/gherkin3,concertman/gherkin3,moreirap/gherkin3,thetutlage/gherkin3,dg-ratiodata/gherkin3,vincent-psarga/gherkin3,thiblahute/gherkin3,thiblahute/gherkin3,dirkrombauts/gherkin3,thiblahute/gherkin3,moreirap/gherkin3,cucumber/gherkin3,chebizarro/gherkin3,amaniak/gherkin3,chebizarro/gherkin3,concertman/gherkin3,chebizarro/gherkin3,thetutlage/gherkin3,Zearin/gherkin3,dirkrombauts/gherkin3,hayd/gherkin3,Zearin/gherkin3,pjlsergeant/gherkin,cucumber/gherkin3,thetutlage/gherkin3,SabotageAndi/gherkin,amaniak/gherkin3,hayd/gherkin3,chebizarro/gherkin3,cucumber/gherkin3,pjlsergeant/gherkin,concertman/gherkin3,pjlsergeant/gherkin,pjlsergeant/gherkin,pjlsergeant/gherkin,amaniak/gherkin3,vincent-psarga/gherkin3,chebizarro/gherkin3,cucumber/gherkin3,dirkrombauts/gherkin3,SabotageAndi/gherkin,araines/gherkin3,dirkrombauts/gherkin3,SabotageAndi/gherkin,curzona/gherkin3,thiblahute/gherkin3,Zearin/gherkin3