Fix some function names (#292)

Author: roflmaostc

README.md

@@ -17,7 +17,7 @@
 > Collection of utilities for testing forward- and reverse-mode AD sensitivities.
 
 `ChainRulesTestUtils.jl` is designed to help you test `ChainRulesCore.frule` and `ChainRulesCore.rrule` methods.
-The main entry points are `ChainRulesTestUtils.frule_test`, `ChainRulesTestUtils.rrule_test`, and `ChainRulesTestUtils.test_scalar`
+The main entry points are `ChainRulesTestUtils.test_frule`, `ChainRulesTestUtils.test_rrule`, and `ChainRulesTestUtils.test_scalar`
 Currently this is done via testing the rules against numerical differentiation (using [`FiniteDifferences.jl`](https://github.com/JuliaDiff/FiniteDifferences.jl)).
 
 `ChainRulesTestUtils.jl` is separate from [`ChainRulesCore.jl`](https://github.com/JuliaDiff/ChainRulesCore.jl) so that it can be a test-only dependency, allowing it to have potentially heavy dependencies, while keeping `ChainRulesCore.jl` as light-weight as possible.