Fix ENV.get('EPSILON') and add a unit test

[dsmilkov]

Epsilon was 1e-4 for 32bit, and 1e-8 for 16bit, which is the opposite of the correct value.

BUG

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This change is 

[caisq]

Thanks for the quick fix!

Reviewable status: 0 of 1 approvals obtained (waiting on @dsmilkov and @caisq)

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src/environment.ts, line 326 at r1 (raw file):

      }
      return EPSILON_FLOAT16;

optional style nit: does it make sense to use if/else here?

[caisq]

Reviewable status: complete! 1 of 1 approvals obtained (waiting on @dsmilkov and @caisq)

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src/environment.ts, line 326 at r1 (raw file):

Previously, caisq (Shanqing Cai) wrote…

      }
      return EPSILON_FLOAT16;

optional style nit: does it make sense to use if/else here?

Or use the ternary operator.

[dsmilkov]

Reviewed 2 of 2 files at r1, 1 of 1 files at r2.
Reviewable status: complete! 1 of 1 approvals obtained (waiting on @caisq)

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src/environment.ts, line 326 at r1 (raw file):

Previously, caisq (Shanqing Cai) wrote…

Or use the ternary operator.

Done. Switched to ternary op.