Updated stream json objects to be more parse friendly (#1010)

* Added custom marshaller for Entry

Signed-off-by: Joe Elliott <number101010@gmail.com>

* Added comment and test

Signed-off-by: Joe Elliott <number101010@gmail.com>

* Fixed spelling error

* Added a custom marshaller to map entries => values

* Added support for labels

Signed-off-by: Joe Elliott <number101010@gmail.com>

* Changed test to only check to the microsecond level

Signed-off-by: Joe Elliott <number101010@gmail.com>

* Extended Entry tests

Signed-off-by: Joe Elliott <number101010@gmail.com>

* Swapped to nanosecs encoded as strings

* Cleaned up docs with new loki paths.  Removed references to deprecated endpoints

* Added support for /loki/api/v1/push

Signed-off-by: Joe Elliott <number101010@gmail.com>

* Removed obsolete comment

Signed-off-by: Joe Elliott <number101010@gmail.com>

* Updated docs for new push endpoint

Signed-off-by: Joe Elliott <number101010@gmail.com>

* Ran gofmt on test file

Signed-off-by: Joe Elliott <number101010@gmail.com>

* Set GOGC=20 on test to avoid out of memory issue in circle ci

Signed-off-by: Joe Elliott <number101010@gmail.com>