merge latest stable fixes from develop branch

* develop: (31 commits)
  docs: fix contrast on highlighted code text (#73)
  feat: improve error handling for log_metrics decorator (#71)
  chore(deps): bump graphql-playground-html from 1.6.19 to 1.6.25 in /docs
  feat: add high level imports (#70)
  fix: correct env var name for publish to pypi test (#69)
  chore: version bump (#68)
  feat: add capture_cold_start_metric for log_metrics (#67)
  chore(deps): bump websocket-extensions from 0.1.3 to 0.1.4 in /docs (#66)
  feat: automate publishing to pypi (#58)
  feat: add pre-commit hooks (#64)
  improv: include example tests in `make tests` (#63)
  chore: rename Makefile target docs-dev to docs-local (#65)
  improv: better namespace/dimension handling for Metrics (#62)
  docs: build on master only
  chore: correct docstring for log_metrics
  chore: fix typo in metrics doc
  chore: Correct test comment
  chore: remove unused import
  chore: formatting
  feat: update Metrics interface to resemble tracer & logger: use "service" as its namespace.
  ...

Author: heitorlessa

.flake8

@@ -1,5 +1,5 @@
 [flake8]
-exclude = docs, .eggs, setup.py, example, .aws-sam
+exclude = docs, .eggs, setup.py, example, .aws-sam, .git, dist, *.md, *.yaml, example/samconfig.toml, *.txt, *.ini
 ignore = E203, E266, W503, BLK100, W291, I004
 max-line-length = 120
 max-complexity = 15

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,46 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: bug, triage
+assignees: ''
+
+---
+
+<!--- Provide a general summary of the issue in the Title above -->
+<!--- How has this issue affected you? What are you trying to accomplish? -->
+
+**What were you trying to accomplish?**
+
+## Expected Behavior
+<!--- If you're describing a bug, tell us what should happen -->
+<!--- If you're suggesting a change/improvement, tell us how it should work -->
+
+## Current Behavior
+<!--- If describing a bug, tell us what happens instead of the expected behavior -->
+<!--- If suggesting a change/improvement, explain the difference from current behavior -->
+
+## Possible Solution
+<!--- Not obligatory, but suggest a fix/reason for the bug, -->
+<!--- or ideas how to implement the addition or change -->
+
+## Steps to Reproduce (for bugs)
+<!--- Provide a link to a live example, or an unambiguous set of steps to -->
+<!--- reproduce this bug. Include code to reproduce, if relevant -->
+1.
+2.
+3.
+4.
+
+## Environment
+
+* **Powertools version used**:
+* **Packaging format (Layers, PyPi)**:
+* **AWS Lambda function runtime:**
+* **Debugging logs**
+
+> [How to enable debug mode](https://awslabs.github.io/aws-lambda-powertools-python/#debug-mode)**
+
+```python
+# paste logs here
+```