Wrap puppetlabs_spec_helper in a begin/rescue
Wrap puppetlabs_spec_helper in a begin/rescue

This Rakefile includes extra tasks beyond the standard set included with
spechelper. Wrapping the spechelper load in a begin/rescue allows using these
custom tasks without having the puppetlabs_spec_helper gem installed.

SmartInfrastructures/fuel-library-dev,SmartInfrastructures/fuel-library-dev,zhaochao/fuel-library,zhaochao/fuel-library,stackforge/fuel-library,huntxu/fuel-library,SmartInfrastructures/fuel-library-dev,eayunstack/fuel-library,stackforge/fuel-library,ddepaoli3/fuel-library-dev,eayunstack/fuel-library,huntxu/fuel-library,eayunstack/fuel-library,ddepaoli3/fuel-library-dev,xarses/fuel-library,zhaochao/fuel-library,slystopad/fuel-lib,Metaswitch/fuel-library,xarses/fuel-library,huntxu/fuel-library,xarses/fuel-library,SmartInfrastructures/fuel-library-dev,huntxu/fuel-library,zhaochao/fuel-library,SmartInfrastructures/fuel-library-dev,Metaswitch/fuel-library,slystopad/fuel-lib,ddepaoli3/fuel-library-dev,eayunstack/fuel-library,Metaswitch/fuel-library,slystopad/fuel-lib,Metaswitch/fuel-library,xarses/fuel-library,zhaochao/fuel-library,huntxu/fuel-library,eayunstack/fuel-library,slystopad/fuel-lib,ddepaoli3/fuel-library-dev,stackforge/fuel-library,ddepaoli3/fuel-library-dev,stackforge/fuel-library