Correct copyNodeModules use case

README.md

@@ -79,7 +79,7 @@ module.exports = {
 | norpc | *Boolean* | false | Prevent solidity-coverage from launching its own testrpc. Useful if you are managing a complex test suite with a [shell script](https://github.com/OpenZeppelin/zeppelin-solidity/blob/ed872ca0a11c4926f8bb91dd103bea1378a3384c/scripts/coverage.sh) |
 | testCommand | *String* | `truffle test` |  Run an arbitrary test command. ex: `mocha --timeout 5000`. NB: Also set the `port` option to whatever your tests require (probably 8545). |
 | testrpcOptions | *String* | `--port 8555` | options to append to a command line invocation of testrpc. NB: Using this overwrites the defaults so always specify a port in this string *and* in the `port` option |
-| copyNodeModules | *Boolean* | false | Copies `node_modules` into the coverage environment. May significantly increase the time for coverage to complete if enabled. Useful if your `npm test` scripts rely on `node_modules` packages | 
+| copyNodeModules | *Boolean* | false | Copies `node_modules` into the coverage environment. May significantly increase the time for coverage to complete if enabled. Useful if your contracts import solidity files from an npm installed package. | 
 | skipFiles | *Array* | `['Migrations.sol']` | Array of contracts (with paths expressed relative to the `contracts` directory) that should be skipped when doing instrumentation. `Migrations.sol` is skipped by default, and does not need to be added to this configuration option if it is used. |
 | dir | *String* | `.` | Solidity-coverage copies all the assets in your root directory (except `node_modules`) to a special folder where it instruments the contracts and executes the tests. `dir` allows you to define a relative path from the root directory to those assets. Useful if your contracts & tests are within their own folder as part of a larger project.|