Include capitalised versions of environment variables

[skulltech]

Some programs check for the HTTP_PROXY, HTTPS_PROXY and environment variables like this instead of the usual lowercase ones. One example I could give right now is the Ruby package manager gem (see this stackoverflow answer).

[himanshub16]

I've merged this PR. But the changes should be made to bash.sh as well.

[himanshub16]

I would recommend having capitalised variables as aliases to small case variables.
For example,

HTTP_PROXY=$http_proxy

If you are going this way, then it would require you to modify the environment.sh file as well

[skulltech]

Good call about editing bash.sh. And using aliases are also neat, that could be done. Opening the previous pull request to continue on this would've been nice, but I'm not entirely sure if that can be done or not.

[skulltech]

I did not implemented aliases like you recommended, cause that may make the intention of the program unclear. We are trying to export two separate environment variables HTTP_PROXY and http_proxy, so I think exporting them normally would be better.

[skulltech]

@himanshub16 Pull request #25 fixes this. Let me know if there are any problem and I'll push more commits ( if there are any problem ).