If the perl version is 5.2 change it to 5.20

For consistency, now that perl 5.20 is supported, handle the special
case of version "5.2" in the same way that "5.1" was handled previously
(3f71aa3707a10ee214489520e96fef87fbaf7109)

Note: this was pointed out to me by @haarg
Fixed git fetch
Added git reset after fetch

It fixes situation when working copy were modified and we want to do git checkout.
Split perl version logic into if/else block - #279

Split the special perl logic/handling for 5.1/5.10 and 5.2/5.20 into a
multi-line if/elsif/else block for better readability.

(this was requested by @joshk)
Additional stylistic changes (remove 'return' calls) - #279

Removed return statements in the new perl 5.1/5.10 and 5.2/5.20
version handling, as requested

@joshk - thanks for the feedback and giving me the chance to update to
follow your style guidlines. As you can probably guess, I don't write in
ruby too much :)
Merge pull request #279 from vanstyn/master

If the perl version is 5.2 change it to 5.20
Bumping default go version and aliases for 1.3.1
Merge pull request #283 from meatballhat/bumping-go-for-1.3.1

Bumping default go version and aliases for 1.3.1
Use HTTPS for Rust downloads

https://github.com/rust-lang/rust/issues/16123 is now fixed.
Merge pull request #284 from SimonSapin/patch-1

Use HTTPS for Rust downloads
Use  --verbose when building Rust code

When things go wrong, the default (non verbose) output from Cargo can be as unhelpful as [`subcommand failed with signal: 11`](https://travis-ci.org/servo/rust-cssparser/builds/32654281)
Merge pull request #286 from SimonSapin/patch-2

Use  --verbose when building Rust code
Display key fingerprint
Fix specs
Provide a valid ssh key for specs
Set ssh_key to nil in specs testing for not setting source_key
No need for regexp when checking ssh key installation
Merge pull request #287 from travis-ci/ps-key-fingerprint

Display key fingerprint for SSH key
Merge pull request #281 from ayufan/fixed/git_fetch

Fixed git fetch