One option is to use a cache breaker, but this is an irritating process. Basically you just add a random number to the end of your script inclusion script.
So instead of:
Then you basically change the magic number every time you update the script, which WILL result in the new script being reloaded regardless to the browser settings. In development, this is still a gigantic pain in the arse.
Fortunately there is a solution. On a PC hit CTRL+SHIFT+i or on a Mac hit CMD+Option+i, to bring up the developer tools. This will bring up the developer tools, now locate the gear icon in the bottom right corner:
Then under the General Tab, select Disable cache: