HISTORY.md release notes for 1.2.2

Updated release notes in HISTORY

Merge pull request TileDB-Inc#394 from TileDB-Inc/ttd/history-file

Update README and add HISTORY.md file

Merge pull request TileDB-Inc#230 from TileDB-Inc/walk

Adding a tiledb_walk function and fixing minor URI bug.

Change README.md

Merge pull request TileDB-Inc#22 from TileDB-Inc/dev

Metadata bug fix and minor additions to the C API

Merge pull request TileDB-Inc#9 from TileDB-Inc/dev

Release 0.6.0

Merge pull request TileDB-Inc#63 from Intel-HLS/dev

Metadata bug fix

Merge pull request TileDB-Inc#61 from Intel-HLS/dev

Now TileDB builds with cmake

Merge pull request TileDB-Inc#58 from Intel-HLS/dev

Version 0.5.0