Fixing race condition in rule validation

Merge pull request #18 from dgraph-io/naman/sort

fix(validate): fix race condition in rules sort

Adding order to the execution of validation rules

Merge pull request #17 from dgraph-io/aman/add_order_to_rules

chore: adding order to the validation rules

Added validation for directive arguments

Merge pull request #16 from dgraph-io/anurags92/gwlparserfix

fix(Parser): Add directive argument validator

Remove support for String --> Int coercing

Merge pull request #15 from dgraph-io/jatin/GRAPHQL-1081

fix(GRAPHQL): Remove support of String --> int32 coercion in variables.

v2.1.8: Merge pull request #14 from dgraph-io/jatin/Fix-stringError

fix(GraphQL): fix error while validation when we give Int or Float to String.

changed string validation

Merge pull request #13 from dgraph-io/jatin/Fix-stringPanic

fix(GraphQL): fix validation when we give non-string value in variable and expected type is string.

added variable support in validation hooks

Merge pull request #12 from dgraph-io/jatin/GRAPHQL-1007

Fixes: GRAPHQL-1007
We have allowed to paas @cascade arguments through variables in dgraph. For that we needed input validations check which is added in this library.

Added Input coercion for Integers.

Merge pull request #11 from dgraph-io/jatin/GRAPHQL-1006

Fixes GRAPHQL-1006
In this PR we have added input coercion for Integers which are passed in variables.
Previously this code was part of dgraph.

v2.1.4: Merge pull request #10 from dgraph-io/jatin/fixIdBug

fix(GraphQL): Fix bug that got introduced in last commit , which doesn't allow string value in [ID] to be coerced to list.

v2.1.2: Merge pull request #8 from dgraph-io/jatin/GRAPHQL-745

fix(GraphQL): This PR change the coerced slice to type interface.