adds info on updating/adding tests to spectest docs
adds info on updating/adding tests to spectest docs

kelcecil/securedrop,chadmiller/securedrop,heartsucker/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,kelcecil/securedrop,chadmiller/securedrop,conorsch/securedrop,heartsucker/securedrop,harlo/securedrop,jaseg/securedrop,jeann2013/securedrop,chadmiller/securedrop,jaseg/securedrop,jaseg/securedrop,conorsch/securedrop,jeann2013/securedrop,heartsucker/securedrop,ageis/securedrop,conorsch/securedrop,jrosco/securedrop,conorsch/securedrop,pwplus/securedrop,pwplus/securedrop,pwplus/securedrop,jrosco/securedrop,heartsucker/securedrop,ehartsuyker/securedrop,jrosco/securedrop,kelcecil/securedrop,garrettr/securedrop,jaseg/securedrop,jeann2013/securedrop,jaseg/securedrop,chadmiller/securedrop,chadmiller/securedrop,jaseg/securedrop,harlo/securedrop,garrettr/securedrop,ageis/securedrop,garrettr/securedrop,heartsucker/securedrop,pwplus/securedrop,pwplus/securedrop,harlo/securedrop,jrosco/securedrop,jrosco/securedrop,harlo/securedrop,jeann2013/securedrop,micahflee/securedrop,garrettr/securedrop,jrosco/securedrop,pwplus/securedrop,micahflee/securedrop,kelcecil/securedrop,jeann2013/securedrop,harlo/securedrop,ehartsuyker/securedrop,micahflee/securedrop,ageis/securedrop,micahflee/securedrop,ehartsuyker/securedrop,conorsch/securedrop,chadmiller/securedrop,kelcecil/securedrop,jeann2013/securedrop,ageis/securedrop,harlo/securedrop,ehartsuyker/securedrop,kelcecil/securedrop