All URL is case-sensitive within the applause-button

[LazyRen]

IMHO, some part must not be taken as case-sensitve.

I just noticed this while playing around with #33.

I have reconfigured my blog setting to use lowercase for the hostname. (e.g. LazyRen.github.io/post-link -> lazyren.github.io/post-link)
But unfortunatelly, this erased all previously stored clap-count...

~/blog master                                                                                                                                                                                                                                                                 
❯ curl 'https://api.applause-button.com/get-multiple' \
  -H 'Content-Type: text/plain' --data-binary \
'["Applause-button.com/"]'        
[]%                                                                                                                                                                                                                                                                            

~/blog master                                                                                                                                                                                                                                                                 
❯ curl 'https://api.applause-button.com/get-multiple' \
  -H 'Content-Type: text/plain' --data-binary \
'["applause-button.com/"]'
[{"claps":42135,"sourceIp":"37.120.201.188","url":"applause-button.com/"}]%