v0.17.18: Update latest substrate (#776)

* update latest substrate polkadot-master

* fix test compilation

* bump version to 0.7.18

* bump impl_version

* update substrate

* Revert "Instantiate environment with asynchronous API (#768)"

This reverts commit 989db4b8.

* update substrate

* remove unused parameter type

* bump trie-db version for tests

* fix collator test

* update substrate

* remove unnecessary service changes

statement-table/Cargo.toml

 [package]
 name = "polkadot-statement-table"
-version = "0.7.17"
+version = "0.7.18"
 authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2018"
 

test-parachains/adder/Cargo.toml

 [package]
 name = "adder"
-version = "0.7.17"
+version = "0.7.18"
 authors = ["Parity Technologies <admin@parity.io>"]
 description = "Test parachain which adds to a number as its state transition"
 edition = "2018"

test-parachains/halt/Cargo.toml

 [package]
 name = "halt"
-version = "0.7.17"
+version = "0.7.18"
 authors = ["Parity Technologies <admin@parity.io>"]
 description = "Test parachain which executes forever"
 edition = "2018"

validation/Cargo.toml

 [package]
 name = "polkadot-validation"
-version = "0.7.17"
+version = "0.7.18"
 authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2018"