Fix skipping build command #57

When run with -build='', the following error occurs:

2021/01/10 16:51:52 Running build command!
2021/01/10 16:51:52 Error while building:

The following code in the build() function seems to be for conditionally skipping the build command:

However, the return value of strings.Split will never have length 0 because the provided separator is not empty. If provided an empty string, it will still return a slice containing a single empty string:

If s does not contain sep and sep is not empty, Split returns a slice of length 1 whose only element is s.

If sep is empty, Split splits after each UTF-8 sequence. If both s and sep are empty, Split returns an empty slice.

Maybe the condition could be replaced with if *flagBuild == "" and checked before the call to strings.Split:

 	if *flagBuild == "" { 
 		// If the value of flagBuild is empty then we are done. 
 		return true 
 	} 
 	args := strings.Split(*flagBuild, " ")