Make sol-cov a dependency of @0x/contracts/test-utils

contracts/test-utils/package.json

@@ -37,7 +37,6 @@
         "@0x/abi-gen": "^1.0.17",
         "@0x/dev-utils": "^1.0.18",
         "@0x/sol-compiler": "^1.1.13",
-        "@0x/sol-cov": "^2.1.13",
         "@0x/subproviders": "^2.1.5",
         "@0x/tslint-config": "^1.0.10",
         "@types/bn.js": "^4.11.0",
@@ -60,6 +59,7 @@
         "@0x/types": "^1.3.0",
         "@0x/typescript-typings": "^3.0.4",
         "@0x/utils": "^2.0.6",
+        "@0x/sol-cov": "^2.1.13",
         "@0x/web3-wrapper": "^3.1.5",
         "@types/js-combinatorics": "^0.5.29",
         "bn.js": "^4.11.8",