test_home: Change requiring pygments.css to requiring app-styles.js.
test_home: Change requiring pygments.css to requiring app-styles.js.

This commit changes the tests based on the fact that pygments.css
will no longer be found in the template during testing. pygemnts.css
is being compiled by webpack under app-styles and so we look for the
stubentry for app-styles instead.

Tweaked by tabbott to do a cleaner test.

rht/zulip,rht/zulip,dhcrzf/zulip,timabbott/zulip,hackerkid/zulip,jackrzhang/zulip,dhcrzf/zulip,tommyip/zulip,eeshangarg/zulip,hackerkid/zulip,punchagan/zulip,tommyip/zulip,rht/zulip,shubhamdhama/zulip,eeshangarg/zulip,showell/zulip,zulip/zulip,rht/zulip,brainwane/zulip,dhcrzf/zulip,timabbott/zulip,showell/zulip,dhcrzf/zulip,eeshangarg/zulip,brainwane/zulip,eeshangarg/zulip,shubhamdhama/zulip,zulip/zulip,tommyip/zulip,zulip/zulip,kou/zulip,timabbott/zulip,tommyip/zulip,synicalsyntax/zulip,andersk/zulip,tommyip/zulip,brainwane/zulip,andersk/zulip,hackerkid/zulip,kou/zulip,zulip/zulip,jackrzhang/zulip,eeshangarg/zulip,rishig/zulip,shubhamdhama/zulip,punchagan/zulip,rht/zulip,punchagan/zulip,eeshangarg/zulip,jackrzhang/zulip,dhcrzf/zulip,punchagan/zulip,brainwane/zulip,kou/zulip,rishig/zulip,synicalsyntax/zulip,andersk/zulip,kou/zulip,zulip/zulip,hackerkid/zulip,showell/zulip,punchagan/zulip,brainwane/zulip,punchagan/zulip,synicalsyntax/zulip,rishig/zulip,shubhamdhama/zulip,jackrzhang/zulip,synicalsyntax/zulip,punchagan/zulip,showell/zulip,kou/zulip,shubhamdhama/zulip,timabbott/zulip,hackerkid/zulip,tommyip/zulip,shubhamdhama/zulip,zulip/zulip,synicalsyntax/zulip,jackrzhang/zulip,hackerkid/zulip,rht/zulip,zulip/zulip,showell/zulip,andersk/zulip,eeshangarg/zulip,showell/zulip,timabbott/zulip,hackerkid/zulip,rht/zulip,andersk/zulip,jackrzhang/zulip,andersk/zulip,andersk/zulip,kou/zulip,brainwane/zulip,synicalsyntax/zulip,dhcrzf/zulip,brainwane/zulip,rishig/zulip,rishig/zulip,jackrzhang/zulip,showell/zulip,rishig/zulip,rishig/zulip,shubhamdhama/zulip,kou/zulip,timabbott/zulip,synicalsyntax/zulip,dhcrzf/zulip,tommyip/zulip,timabbott/zulip