Add `_.keys` test for string objects.
Add `_.keys` test for string objects.

af7/lodash,Lottid/lodash,zestia/lodash,Xotic750/lodash,joshuaprior/lodash,studiowangfei/lodash,jacwright/lodash,polarbird/lodash,Moykn/lodash,stewx/lodash,Andrey-Pavlov/lodash,polarbird/lodash,rtorr/lodash,mshoaibraja/lodash,IveWong/lodash,msmorgan/lodash,chrootsu/lodash,MaxPRafferty/lodash,julianocomg/lodash,ricardohbin/lodash,woldie/lodash,dgoncalves1/lodash,jzning-martian/lodash,reggi/lodash,woldie/lodash,lzheng571/lodash,ajefremovs/lodash,bnicart/lodash,PhiLhoSoft/lodash,gdi2290/lodash,nsamarcos/lodash,xiwc/lodash,chrootsu/lodash,xiwc/lodash,mshoaibraja/lodash,AndBicScadMedia/lodash,zhangguangyong/lodash,phillipalexander/lodash,lekkas/lodash,r14r/fork_javascript_lodash,IveWong/lodash,enng0227/lodash,tquetano-r7/lodash,ror/lodash,r14r-work/fork_javascript_lodash,timruffles/lodash,benweet/lodash,schnerd/lodash,mshoaibraja/lodash,lzheng571/lodash,Lottid/lodash,Droogans/lodash,Jaspersoft/lodash,steelsojka/lodash,dgoncalves1/lodash,joshuaprior/lodash,tejokumar/lodash,AneesMohammed/lodash,shwaydogg/lodash,andersonaguiar/lodash,leolin1229/lodash,ajefremovs/lodash,MaxPRafferty/lodash,andersonaguiar/lodash,r14r/fork_javascript_lodash,youprofit/lodash,Moykn/lodash,krahman/lodash,schnerd/lodash,neouser99/lodash,PhiLhoSoft/lodash,benweet/lodash,therebelbeta/lodash,phillipalexander/lodash,reggi/lodash,studiowangfei/lodash,joshuaprior/lodash,hafeez-syed/lodash,xixilive/lodash,gdi2290/lodash,samuelbeek/lodash,IveWong/lodash,imjerrybao/lodash,enng0227/lodash,Xotic750/lodash,codydaig/lodash,AneesMohammed/lodash,shwaydogg/lodash,julianocomg/lodash,Moykn/lodash,beaugunderson/lodash,dgoncalves1/lodash,developer-prosenjit/lodash,neouser99/lodash,Lottid/lodash,r14r/fork_javascript_lodash,ror/lodash,felixshu/lodash,justintung/lodash,lekkas/lodash,studiowangfei/lodash,naoina/lodash,tonyonodi/lodash,xixilive/lodash,rlugojr/lodash,ricardohbin/lodash,af7/lodash,nsamarcos/lodash,zestia/lodash,zhangguangyong/lodash,naoina/lodash,andersonaguiar/lodash,jzning-martian/lodash,youprofit/lodash,prawnsalad/lodash,jacwright/lodash,jshanson7/lodash,bnicart/lodash,codydaig/lodash,krrg/lodash,mjosh954/lodash,steelsojka/lodash,javiosyc/lodash,therebelbeta/lodash,ajefremovs/lodash,r14r-work/fork_javascript_lodash,beaugunderson/lodash,felixshu/lodash,Jaspersoft/lodash,AndBicScadMedia/lodash,xiwc/lodash,tquetano-r7/lodash,tonyonodi/lodash,jshanson7/lodash,mjosh954/lodash,samuelbeek/lodash,bnicart/lodash,greyhwndz/lodash,jasnell/lodash,tgriesser/lodash,Andrey-Pavlov/lodash,rtorr/lodash,Droogans/lodash,boneskull/lodash,transGLUKator/lodash,lekoaf/lodash,imjerrybao/lodash,gutenye/lodash,woldie/lodash,stewx/lodash,tgriesser/lodash,lekkas/lodash,timruffles/lodash,krahman/lodash,jshanson7/lodash,jasnell/lodash,BernhardRode/lodash,hitesh97/lodash,transGLUKator/lodash,greyhwndz/lodash,felixshu/lodash,youprofit/lodash,zhangguangyong/lodash,BernhardRode/lodash,stewx/lodash,prawnsalad/lodash,tejokumar/lodash,PhiLhoSoft/lodash,prawnsalad/lodash,nsamarcos/lodash,hitesh97/lodash,BernhardRode/lodash,transGLUKator/lodash,nbellowe/lodash,nbellowe/lodash,developer-prosenjit/lodash,jasnell/lodash,julianocomg/lodash,Jaspersoft/lodash,jzning-martian/lodash,timruffles/lodash,krrg/lodash,hitesh97/lodash,jacwright/lodash,enng0227/lodash,Andrey-Pavlov/lodash,imjerrybao/lodash,AneesMohammed/lodash,gutenye/lodash,huyinghuan/lodash,hafeez-syed/lodash,boneskull/lodash,phillipalexander/lodash,gutenye/lodash,greyhwndz/lodash,javiosyc/lodash,zestia/lodash,polarbird/lodash,reggi/lodash,neouser99/lodash,msmorgan/lodash,AndBicScadMedia/lodash,r14r-work/fork_javascript_lodash,MaxPRafferty/lodash,developer-prosenjit/lodash,samuelbeek/lodash,leolin1229/lodash,therebelbeta/lodash,krrg/lodash,codydaig/lodash,tgriesser/lodash,hafeez-syed/lodash,lekoaf/lodash,krahman/lodash,ricardohbin/lodash,lzheng571/lodash,shwaydogg/lodash,tquetano-r7/lodash,huyinghuan/lodash,lekoaf/lodash,chrootsu/lodash,Xotic750/lodash,Droogans/lodash,af7/lodash,justintung/lodash,schnerd/lodash,xixilive/lodash,benweet/lodash,justintung/lodash,tejokumar/lodash,javiosyc/lodash,rtorr/lodash,nbellowe/lodash,mjosh954/lodash,ror/lodash,naoina/lodash,leolin1229/lodash,rlugojr/lodash,huyinghuan/lodash