chore: attempt build fix

`go tool cover` and `go test` create package paths differently
when code is not inside a "src" directory, and circleci doesn't clone
code into a src directory.

golang/go#17269

circle.yml

@@ -3,8 +3,11 @@ test:
         - go vet ./...
         - go get -u github.com/jstemmer/go-junit-report
         - mkdir -p $CIRCLE_TEST_REPORTS/junit
-        - go test -v ./... | go-junit-report > $CIRCLE_TEST_REPORTS/junit/report.xml
         - mkdir -p $CIRCLE_ARTIFACTS/coverage
+        - mkdir -p .go_workspace/src/github.com/chriscasola/nlp
+        - cp -R nlp/* .go_workspace/src/github.com/chriscasola/nlp/
+        - cd .go_workspace/src/github.com/chriscasola/nlp/
+        - go test -v ./... | go-junit-report > $CIRCLE_TEST_REPORTS/junit/report.xml
         - go test -covermode=count -coverprofile=$CIRCLE_ARTIFACTS/coverage.out ./...
         - go tool cover -html=$CIRCLE_ARTIFACTS/coverage.out -o $CIRCLE_ARTIFACTS/coverage.html
         - go tool cover -func=$CIRCLE_ARTIFACTS/coverage.out -o $CIRCLE_ARTIFACTS/coverage.txt