Syntax highlight `Int[]` etc.

[karajan9]

It would be nice to highlight the types in array creation statements like Int[] the same way they are highlighted with Vector{Int}().
As @pfitzseb mentioned on Slack, simply highlighting everything before [] runs into problems with a[] after a = Ref{Int}(), to which he suggested to highlight only TitleCase.

Pros:

• extra highlighting makes the code easier to read
• consistency with highlighting types elsewhere

Cons:

• it will give a false negative for people who don't use TitleCase for their own types
• it will give a false positive for people who use TitleCase for their variables and use Ref

Since the Julia manual suggests "modules and type names use capitalization and camel case: module SparseArrays, struct UnitRange." and the next logical step would to use everything but this for variables, one could argue that the cons shouldn't affect too many people.