Fix type definition for Resolver

[rafalp]

Our current type annotation for Resolver doesn't support resolvers accepting arguments, thus introducing noise to Mypy that resolver function doesn't meet the signature of [Any, GraphQLResolveInfo].

This problem is known to MyPy authors, but in the meantime we should update our Resolver type to be more forgiving so dev tools and code linters don't confuse devs using Ariadne.

This PR changes annotation to Callable[..., Any].

[codecov]

Codecov Report

Merging #79 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master    #79   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files          37     37           
  Lines        1119   1119           
=====================================
  Hits         1119   1119

Impacted Files	Coverage Δ
ariadne/types.py	100% <100%> (ø)	⬆️

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