🔒 Fix missing HTTPS on links

CONTRIBUTING.md

@@ -61,5 +61,5 @@ language itself. Please note the following hints for your Ruby code:
 #### Comply with the Ruby standard (ISO/IEC 30170:2012)
 
 mruby is currently targeting to execute Ruby code which complies to ISO/IEC
-30170:2012 (http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=59579),
+30170:2012 (https://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=59579),
 unless there's a clear reason, e.g. the latest Ruby has changed behavior from ISO.

README.md

@@ -86,12 +86,12 @@ Please ask us if you want to distribute your code under another license.
 ## How to Contribute
 
 See the [contribution guidelines][contribution-guidelines], and then send a pull
-request to <http://github.com/mruby/mruby>.  We consider you have granted
+request to <https://github.com/mruby/mruby>.  We consider you have granted
 non-exclusive right to your contributed code under MIT license.  If you want to
 be named as one of mruby developers, please include an update to the AUTHORS
 file in your pull request.
 
-[ISO-standard]: http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=59579
+[ISO-standard]: https://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=59579
 [build-status-img]: https://travis-ci.org/mruby/mruby.svg?branch=master
 [contribution-guidelines]: https://github.com/mruby/mruby/blob/master/CONTRIBUTING.md
 [travis-ci]: https://travis-ci.org/mruby/mruby

doc/guides/compile.md

@@ -76,7 +76,7 @@ toolchain :clang
 #### Visual Studio 2010, 2012 and 2013
 
 Toolchain configuration for Visual Studio on Windows. If you use the
-[Visual Studio Command Prompt](http://msdn.microsoft.com/en-us/library/ms229859\(v=vs.110\).aspx),
+[Visual Studio Command Prompt](https://msdn.microsoft.com/en-us/library/ms229859\(v=vs.110\).aspx),
 you normally do not have to specify this manually, since it gets automatically detected by our build process.
 ```ruby
 toolchain :visualcpp

mrbgems/mruby-compiler/core/y.tab.c

@@ -16,7 +16,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 /* As a special exception, you may create a larger work that contains
    part or all of the Bison parser skeleton and distribute that work

mrbgems/mruby-random/src/random.c

@@ -19,7 +19,7 @@ To the extent possible under law, the author has dedicated all copyright
 and related and neighboring rights to this software to the public domain
 worldwide. This software is distributed without any warranty.
 
-See <http://creativecommons.org/publicdomain/zero/1.0/>. */
+See <https://creativecommons.org/publicdomain/zero/1.0/>. */
 
 #include <stdint.h>