Add versioning #489

1. 
   skywinder commented at 6:56 pm on December 5, 2017: none

   I’m using upgrading project, which use this library to build native iOS framework https://github.com/beyonderyue/ios-secp256k1

   Can you suggest stable stash commit for using in this library?

   I want to purpose to add tags to a git repo to structurize work and point for users a stable library version.

   Is the 6ad5cdb42a1a8257289a0423d644dcbdeab0f83c a stable version? May I suggest to set a tag 1.0.0 for this to start versionising process?

2. skywinder cross-referenced this on Dec 5, 2017 from issue Git clone feature by skywinder
3. 
   apoelstra commented at 8:19 pm on December 5, 2017: contributor

   dupe of https://github.com/bitcoin-core/secp256k1/issues/286
4. apoelstra closed this on Dec 5, 2017

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Contributors
skywinder apoelstra