minor NEWS update for v1.3.7

Merge pull request facebook#1354 from facebook/dev

Zstandard v1.3.6

Merge pull request facebook#1217 from facebook/dev

fix poolTest for v1.3.5

Merge pull request facebook#1076 from facebook/dev

v1.3.4

Merge pull request facebook#954 from facebook/dev

Release v1.3.3

make clean before zstd-lz4 compatibility tests

to ensure zstd is rebuilt with lz4 support

Merge pull request facebook#859 from terrelln/31

Prepare for ZSTD_WINDOWLOG_MAX == 31

Merge pull request facebook#808 from facebook/dev

Zstandard v1.3.1

Merge pull request facebook#750 from facebook/dev

fixed wrong assert() condition

Merge pull request facebook#686 from facebook/dev

v1.2.0