only run appveyor on master

Apparently AppVeyor works with pull requests now. Might be a good idea to set it to only build for the master branch, until they sort out co-existing with Travis on status indicators.
Printing speed improvements

* print_escaped: simplify, reduce expected number of comparisons
* arrays/tuples: don't duplicate array
Merge pull request #69 from tkelman/patch-1

only run appveyor on master
Merge pull request #70 from JuliaLang/kms/print_updates

Printing speed improvements
implement indents, correct DataType and Symbol printing
Merge pull request #66 from samuelcolvin/indent

Implement indents for printing JSON as per #65
Fix test to accept either ordering of Dict keys.
Add AppVeyor status image

Closes #74
work around JuliaLang/julia#7416
more readable error when serializing modules
include module name in error
Merge pull request #77 from JuliaLang/json-module-error

more readable error when serializing modules
run appveyor on all branches again

now that there is a multi-status app
Merge pull request #79 from tkelman/appveyor-all-branches

run appveyor on all branches again
Add coveralls badge
Tweaks to README
Modern Travis and testing
Update README.md
Try to fix bizzare failure on juliarelease where it seems like JSON gets uninstalled!
Convert to Int before indexing with Char in Array

Regression fix from https://github.com/JuliaLang/julia/pull/8816
Fixes #84