Add anchor and deprecated as NonValidationKeywords for v2019-09 draft

[anicolasgar]

Following #328 and #341 , also $anchor and deprecated were introduced as keywords in draft 2019-09.

See:

• https://json-schema.org/draft/2019-09/json-schema-core.html#rfc.section.8.2.3
• https://json-schema.org/draft/2019-09/json-schema-validation.html#rfc.section.9.3

[codecov-io]

Codecov Report

Merging #351 (967844f) into master (068a3e5) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #351   +/-   ##
=========================================
  Coverage     69.94%   69.94%           
  Complexity      697      697           
=========================================
  Files            80       80           
  Lines          2745     2745           
  Branches        569      569           
=========================================
  Hits           1920     1920           
  Misses          610      610           
  Partials        215      215           

Impacted Files	Coverage Δ	Complexity Δ
...main/java/com/networknt/schema/JsonMetaSchema.java	85.82% <ø> (ø)	16.00 <0.00> (ø)

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[stevehu]

@anicolasgar Thanks a lot for your help.