Update release notes for 0.15.1
Update release notes for 0.15.1

GtTmy/pyeda,GtTmy/pyeda,cjdrake/pyeda,pombredanne/pyeda,sschnug/pyeda,karissa/pyeda,karissa/pyeda,cjdrake/pyeda,karissa/pyeda,sschnug/pyeda,cjdrake/pyeda,pombredanne/pyeda,GtTmy/pyeda,pombredanne/pyeda,sschnug/pyeda