templates: Added github templates for Issues and PRs as well as contributing guide. (thanos-io#368)

Signed-off-by: Bartek Plotka <bwplotka@gmail.com>

Author: bwplotka

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,48 @@
+<!--
+Template relevant to bug reports only!
+
+Keep issue title verbose enough and add prefix telling
+about what components it touches e.g "query:" or ".*:"
+-->
+
+**Thanos, Prometheus and Golang version used**
+
+<!--
+Output of "thanos --version" or docker image:tag used.
+(Double-check if all deployed components/services have expected versions)
+
+If you are using custom build from master branch, have you checked out the tip of the master?
+-->
+
+**What happened**
+
+**What you expected to happen**
+
+**How to reproduce it (as minimally and precisely as possible)**:
+
+**Full logs to relevant components**
+
+<!--
+Uncomment if you would like to post collapsible logs:
+
+<details>Logs
+<p>
+
+```
+```
+
+</p>
+</details>
+-->
+
+**Anything else we need to know**
+
+<!--
+Uncomment and fill if you use not casual environment or if it might be relevant.
+
+**Environment**:
+- OS (e.g. from /etc/os-release):
+- Kernel (e.g. `uname -a`):
+- Others:
+
+-->

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,12 @@
+<!--
+    Keep PR title verbose enough and add prefix telling
+    about what components it touches e.g "query:" or ".*:"
+-->
+
+## Changes
+
+<!-- Enumerate changes you made -->
+
+## Verification
+
+<!-- How you tested it? How do you know it works? -->

CONTRIBUTING.md

@@ -0,0 +1,24 @@
+# Contributing
+
+When contributing not obvious change to Thanos repository, please first
+discuss the change you wish to make via issue or slack, or any other
+method with the owners of this repository before making a change.
+
+Please follow the [code of conduct](CODE_OF_CONDUCT.md) in all your interactions with the project.
+
+## Pull Request Process
+
+1. Read [getting started docs](docs/getting_started.md) and prepare Thanos.
+2. Familarize yourself with [Makefile](Makefile) commands like `format`, `build`, `proto` and `test`.
+3. Keep PRs as small as possible. Chain them if needed (base PR on other PRs).
+4. If you don't have a live object store ready add these envvars to skip tests for these:
+- THANOS_SKIP_GCS_TESTS to skip GCS tests.
+- THANOS_SKIP_S3_AWS_TESTS to skip AWS tests.
+
+If you skip both of these, the store specific tests will be run against memory object storage only.
+CI runs GCS and inmem tests only for now. Not having these variables will produce auth errors against GCS or AWS tests.
+
+5. If your change affects users (adds or removes feature) consider adding the item to [CHANGELOG](CHANGELOG.md)
+6. You may merge the Pull Request in once you have the sign-off of at least one developers with write access, or if you
+   do not have permission to do that, you may request the second reviewer to merge it for you.
+7. If you feel like your PR waits too long for a review, feel free to ping [`#thanos-dev`](https://join.slack.com/t/improbable-eng/shared_invite/enQtMzQ1ODcyMzQ5MjM4LWY5ZWZmNGM2ODc5MmViNmQ3ZTA3ZTY3NzQwOTBlMTkzZmIxZTIxODk0OWU3YjZhNWVlNDU3MDlkZGViZjhkMjc) channel on our slack for review!

docs/getting_started.md

@@ -8,7 +8,8 @@ See [this](storage.md) for up-to-date list of available object stores for Thanos
 
 ## Requirements
 
-* One or more [Prometheus](https://prometheus.io) v2.0.0 installations
+* One or more [Prometheus](https://prometheus.io) v2.2.1+ installations (v2.0.0 works too but is not recommended)
+* golang 1.10+
 * An object storage bucket (optional)
 
 ## Get Thanos!