I did find the same question being asked in stack overflow and I did try some of their solutions but none worked for me. Some solutions I tried were,
1) Removing the proxy
2) Changing the source of the gem file from 'https://rubygems.org' to 'http://rubygems.org'
None of these were able to solve this problem for me. Below is the error I get when I run bundle install. Note: I have being installing gems in this way for some time. I recently only started getting this error. Does anyone have any idea as to why this happens? Thanks in advance!
The dependency tzinfo-data (>= 0) will be unused by any of the platforms
Bundler is installing for. Bundler is installing for ruby but the dependency
is only for x86-mingw32, x86-mswin32, x64-mingw32, java. To add those
platforms to the bundle, run `bundle lock --add-platform mingw, mswin,
x64_mingw, jruby`.
Fetching source index from https://rubygems.org/
Retrying fetcher due to error (2/4): Bundler::HTTPError Could not fetch
specs from https://rubygems.org/
Retrying fetcher due to error (3/4): Bundler::HTTPError Could not fetch
specs from https://rubygems.org/
Retrying fetcher due to error (4/4): Bundler::HTTPError Could not fetch
specs from https://rubygems.org/
Could not fetch specs from https://rubygems.org/
Process finished with exit code 17
UPDATE
I went to the site http://isup.me/rubygems.org and I get the message,
It's just you. http://rubygems.org is up.
After following the instructions given here, I found that I have not removed my proxy settings entirely.
So thanks to this user I was able to resolve my question!