non_upper_case_globals warnings building the test suite

[dtolnay]

cargo test on the current master branch passes but emits the following warnings. It would be nice to either suppress these with an attribute or just fix the case of these const names to what rustc wants.

warning: constant `value1` should have an upper case name
 --> tests/tests.rs:5:11
  |
5 |     const value1: u32 = const_random!(u32);
  |           ^^^^^^ help: convert the identifier to upper case: `VALUE1`
  |
  = note: `#[warn(non_upper_case_globals)]` on by default

warning: constant `value2` should have an upper case name
 --> tests/tests.rs:6:11
  |
6 |     const value2: u32 = const_random!(u32);
  |           ^^^^^^ help: convert the identifier to upper case: `VALUE2`

warning: constant `value1` should have an upper case name
  --> tests/tests.rs:14:11
   |
14 |     const value1: i64 = const_random!(i64);
   |           ^^^^^^ help: convert the identifier to upper case: `VALUE1`

warning: constant `value2` should have an upper case name
  --> tests/tests.rs:15:11
   |
15 |     const value2: i64 = const_random!(i64);
   |           ^^^^^^ help: convert the identifier to upper case: `VALUE2`

warning: constant `value1` should have an upper case name
  --> tests/tests.rs:24:11
   |
24 |     const value1: u128 = const_random!(u128);
   |           ^^^^^^ help: convert the identifier to upper case: `VALUE1`

warning: constant `value2` should have an upper case name
  --> tests/tests.rs:25:11
   |
25 |     const value2: u128 = const_random!(u128);
   |           ^^^^^^ help: convert the identifier to upper case: `VALUE2``