Remove use of inexact-spread Flow lint

Summary:
After changes to the semantics of spread, this lint is no longer relevant and will be removed in an upcoming version of Flow.

Changelog: [Internal]

Reviewed By: jbrown215

Differential Revision: D19241147

fbshipit-source-id: 2cad93725055601f2ceaa2379ed3643f136ff69b

Author: gkz

.flowconfig

@@ -70,7 +70,6 @@ untyped-type-import=warn
 nonstrict-import=warn
 deprecated-type=warn
 unsafe-getters-setters=warn
-inexact-spread=warn
 unnecessary-invariant=warn
 signature-verification-failure=warn
 deprecated-utility=error

.flowconfig.android

@@ -70,7 +70,6 @@ untyped-type-import=warn
 nonstrict-import=warn
 deprecated-type=warn
 unsafe-getters-setters=warn
-inexact-spread=warn
 unnecessary-invariant=warn
 signature-verification-failure=warn
 deprecated-utility=error

template/_flowconfig

@@ -59,7 +59,6 @@ untyped-type-import=warn
 nonstrict-import=warn
 deprecated-type=warn
 unsafe-getters-setters=warn
-inexact-spread=warn
 unnecessary-invariant=warn
 signature-verification-failure=warn
 deprecated-utility=error