Too Flexible File Permission. Should Have Status Check Before Removing File.

[The permission seems to be too flexible :](https://github.com/bcgov-c/data-linking/blob/develop-2.0/cdi-linking/cdilinker/linker/base.py#L276)

The permission seems to be too flexible. And assumption is we are on some sort of Unix environment. However the latter is not a problem due to containerizing our code.

[Is not it better to check the status/return value of the previous subprocess.call statement before removing the script file?](https://github.com/bcgov-c/data-linking/blob/develop/cdi-linking/cdilinker/linker/base.py#L278)