DOC: change development instructions from SSH to HTTPS access.
DOC: change development instructions from SSH to HTTPS access.

This is easier to get going, and is the recommended access method
by GitHub itself:
https://help.github.com/articles/which-remote-url-should-i-use/

Also add instructions for pulling from upstream including PRs
by default.

solarjoe/numpy,pizzathief/numpy,maniteja123/numpy,pizzathief/numpy,simongibbons/numpy,Eric89GXL/numpy,Eric89GXL/numpy,rgommers/numpy,madphysicist/numpy,madphysicist/numpy,numpy/numpy,jorisvandenbossche/numpy,pdebuyl/numpy,ahaldane/numpy,jorisvandenbossche/numpy,MSeifert04/numpy,seberg/numpy,mhvk/numpy,madphysicist/numpy,madphysicist/numpy,mhvk/numpy,utke1/numpy,pdebuyl/numpy,ddasilva/numpy,MSeifert04/numpy,Eric89GXL/numpy,maniteja123/numpy,ahaldane/numpy,jakirkham/numpy,b-carter/numpy,bertrand-l/numpy,WarrenWeckesser/numpy,ssanderson/numpy,stuarteberg/numpy,pizzathief/numpy,njase/numpy,charris/numpy,rgommers/numpy,charris/numpy,behzadnouri/numpy,jorisvandenbossche/numpy,utke1/numpy,WarrenWeckesser/numpy,ddasilva/numpy,chatcannon/numpy,mattip/numpy,simongibbons/numpy,mattip/numpy,mhvk/numpy,jakirkham/numpy,endolith/numpy,madphysicist/numpy,njase/numpy,Eric89GXL/numpy,stuarteberg/numpy,rgommers/numpy,jakirkham/numpy,jorisvandenbossche/numpy,njase/numpy,anntzer/numpy,jorisvandenbossche/numpy,seberg/numpy,ContinuumIO/numpy,mattip/numpy,bringingheavendown/numpy,simongibbons/numpy,gfyoung/numpy,mattip/numpy,shoyer/numpy,chatcannon/numpy,grlee77/numpy,mhvk/numpy,abalkin/numpy,abalkin/numpy,shoyer/numpy,pbrod/numpy,ContinuumIO/numpy,pizzathief/numpy,b-carter/numpy,stuarteberg/numpy,pbrod/numpy,stuarteberg/numpy,numpy/numpy,seberg/numpy,pbrod/numpy,grlee77/numpy,ssanderson/numpy,grlee77/numpy,mhvk/numpy,behzadnouri/numpy,solarjoe/numpy,simongibbons/numpy,gfyoung/numpy,bertrand-l/numpy,grlee77/numpy,ddasilva/numpy,endolith/numpy,abalkin/numpy,jakirkham/numpy,pizzathief/numpy,MSeifert04/numpy,pbrod/numpy,pbrod/numpy,numpy/numpy,anntzer/numpy,simongibbons/numpy,solarjoe/numpy,ahaldane/numpy,MSeifert04/numpy,WarrenWeckesser/numpy,ahaldane/numpy,charris/numpy,grlee77/numpy,ahaldane/numpy,gfyoung/numpy,pdebuyl/numpy,anntzer/numpy,seberg/numpy,endolith/numpy,chatcannon/numpy,jakirkham/numpy,tynn/numpy,tynn/numpy,pdebuyl/numpy,WarrenWeckesser/numpy,utke1/numpy,bringingheavendown/numpy,b-carter/numpy,anntzer/numpy,bringingheavendown/numpy,rgommers/numpy,bertrand-l/numpy,ContinuumIO/numpy,shoyer/numpy,tynn/numpy,maniteja123/numpy,endolith/numpy,behzadnouri/numpy,MSeifert04/numpy,shoyer/numpy,ssanderson/numpy,charris/numpy,WarrenWeckesser/numpy,shoyer/numpy,numpy/numpy