test_events.py: Properly check the bot added event dict.
test_events.py: Properly check the bot added event dict.

Previously, the 'services' entry in the bot added event dict,
did not get verified, because the test didn't include a service bot.

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