Add tests/bugfixes for loadConfig (#1059)

- Fixed bug where a user specifies loading of a config with a flag, but if that file isn't found, it loads an `apollo.config.js`. 
	- Ex: `apollo client:check --config=config/apollo.js` would also load `./apollo.config.js` if it couldn't find the specified config. I think if a user is _manually specifying_ a config, it should _only_ load what they specified and throw an error if not found. 
	- This was preventing testing errors, since leaving off a config would just load this repo's config (which wouldn't work)
- Removed the `getSearchPlaces` function. It was extraneous, and misleading. While `search places` is the term that dotenv uses, it is less descriptive than `defaultFileNames`, since that what the search places are–filenames.
- Added `try/catch` around the cosmiconfig's loader, since it can throw on malformed files with an unhelpful error.
- Handled case where `.env` is not a `File`, but a folder or something else. Resolves #1132 
- Split up project type and service name setting, since those being intertwined added unnecessary complexity

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Upcoming
 
+- apollo-language-server
+  - Stop loadConfig from looking up the tree when a --config location is defined [#1059](https://github.com/apollographql/apollo-tooling/pull/1059)
+  - Refactored/documented/tested loadConfig [#1059](https://github.com/apollographql/apollo-tooling/pull/1059)
+
 ## `apollo-codegen-flow@0.32.11`
 
 - `apollo-codegen-flow@0.32.11`