Added support for kwargs in @mock calls.

[rofinn]

Handles @mock calls with keyword arguments (both :parameters and regular :kw). Currently, left the QuoteNode on kwarg values out as it won't be necessary with #20.

Fixes: #19

[rofinn]

invokelatest in Compat (and I think Base) doesn't support kwargs either.

[codecov]

Codecov Report

Merging #21 into master will increase coverage by 0.52%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master     #21      +/-   ##
=========================================
+ Coverage   93.07%   93.6%   +0.52%     
=========================================
  Files           4       2       -2     
  Lines         260     172      -88     
=========================================
- Hits          242     161      -81     
+ Misses         18      11       -7

Impacted Files	Coverage Δ
src/expr.jl	98.9% <100%> (+1.75%)	⬆️
src/Mocking.jl	87.65% <100%> (+0.29%)	⬆️
src/bindings.jl
src/options.jl

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update db52245...05d75e5. Read the comment docs.

[omus]

Addressed in JuliaLang/julia#22646 and JuliaLang/Compat.jl#424 (v0.40)

[omus]

Rebased the PR

[omus]

AppVeyor failure is just being unable to download the 32-bit nightly binaries.