Correctly eat semicolon at the end of DelcareModuleExports

[danez]

Q	A
Bug fix?	yes
Breaking change?	no
New feature?	no
Deprecations?	no
Spec compliancy?	no
Tests added/pass?	yes
Fixed tickets	comma-separated list of tickets fixed by the PR, if any
License	MIT

Without this patch this fails

declare module "foo" { declare module.exports: number; }

but this works

declare module "foo" { declare module.exports: number }

In flow both works.

[codecov-io]

Current coverage is 97.69% (diff: 100%)

Merging #223 into master will increase coverage by <.01%

@@             master       #223   diff @@
==========================================
  Files            19         19          
  Lines          3214       3215     +1   
  Methods         336        336          
  Messages          0          0          
  Branches        838        838          
==========================================
+ Hits           3140       3141     +1   
  Misses           30         30          
  Partials         44         44          

Powered by Codecov. Last update c30a556...ad88d46