providing a better error if _data.json is missing
providing a better error if _data.json is missing

ericgsmith/d7patternlab,dcmouyard/patternlab-php-gesso,trevorkjorlien/elevation-prototype,nadre/erdande,ninjazero/atomic-drupal,peterwilsoncc/underscores-pattern-lab,Wagnerp/patternlab-php,usminteractive/patternlab-php,dcmouyard/patternlab-php-gesso,capognavalerio/patternlab-php,peterwilsoncc/underscores-pattern-lab,capognavalerio/patternlab-php,trevorkjorlien/elevation-prototype,ahebrank/patternlab-php,tweakers-dev/patternlab-php,griff/lisberg-ui,usminteractive/patternlab-php,capognavalerio/patternlab-php,ninjazero/atomic-drupal,rpkoller/patternlab-php,rpkoller/patternlab-php,peterwilsoncc/underscores-pattern-lab,capognavalerio/patternlab-php,savoirfairelinux/patternlab-php-bootstrap-3,swiftagency/patternlab-php,taupecat/patternlab-php,Comi9/patternlab-php,andrewmowe/tmi-patternlab,nadre/erdande,andrewmowe/tmi-patternlab,peterwilsoncc/styleguide,trevorkjorlien/elevation-prototype,Comi9/patternlab-php,taupecat/patternlab-php,shazadx/patternlab-framework,peterwilsoncc/joy949-patterns,amyash/patternlab-php,pattern-lab/patternlab-php,peterwilsoncc/joy949-patterns,Comi9/patternlab-php,nadre/erdande,advisorwebsites/patternlab-php,CreativeOutbreak/ni-patternslab,tweakers-dev/patternlab-php,tweakers-dev/patternlab-php,coreylafferty/patternlab-php-gesso,tweakers-dev/patternlab-php,usminteractive/patternlab-php,foxman209/patternlab-php,DSI-VD/patternlab-vd,CreativeOutbreak/ni-patternslab,vfalconi/patternlab-php,coreylafferty/patternlab-php-gesso,swiftagency/patternlab-php,dcmouyard/patternlab-php-gesso,coreylafferty/patternlab-php-gesso,shazadx/patternlab-framework,ericgsmith/d7patternlab,advisorwebsites/patternlab-php,DSI-VD/patternlab-vd,foxman209/patternlab-php,peterwilsoncc/styleguide,foxman209/patternlab-php,ninjazero/atomic-drupal,amyash/patternlab-php,andrewmowe/tmi-patternlab,swiftagency/patternlab-php,vfalconi/patternlab-php,Wagnerp/patternlab-php,advisorwebsites/patternlab-php,sarahjean/sdd-pl-demo,nadre/erdande,taupecat/patternlab-php,tweakers-dev/patternlab-php,griff/lisberg-ui,dcmouyard/patternlab-php-gesso,advisorwebsites/patternlab-php,trevorkjorlien/elevation-prototype,CreativeOutbreak/ni-patternslab,IOIO72/patternlab-php,peterwilsoncc/styleguide,nadre/erdande,rpkoller/patternlab-php,coreylafferty/patternlab-php-gesso,amyash/patternlab-php,peterwilsoncc/joy949-patterns,savoirfairelinux/patternlab-php-bootstrap-3,vfalconi/patternlab-php,foxman209/patternlab-php,sarahjean/sdd-pl-demo,IOIO72/patternlab-php,IOIO72/patternlab-php,IOIO72/patternlab-php,ahebrank/patternlab-php,andrewmowe/tmi-patternlab,peterwilsoncc/underscores-pattern-lab,sarahjean/sdd-pl-demo,taupecat/patternlab-php,Wagnerp/patternlab-php,Wagnerp/patternlab-php,ahebrank/patternlab-php,ahebrank/patternlab-php,usminteractive/patternlab-php,ericgsmith/d7patternlab,peterwilsoncc/styleguide,ericgsmith/d7patternlab,swiftagency/patternlab-php,vfalconi/patternlab-php,rpkoller/patternlab-php,ninjazero/atomic-drupal,swiftagency/patternlab-php,amyash/patternlab-php,sarahjean/sdd-pl-demo,griff/lisberg-ui,peterwilsoncc/joy949-patterns,DSI-VD/patternlab-vd,Comi9/patternlab-php,DSI-VD/patternlab-vd,griff/lisberg-ui,savoirfairelinux/patternlab-php-bootstrap-3