Adds bug issue template

Integrates with GitHub's issues template feature. Provides fields for
bug summary, suspected causes and additional details such as OS/Python
version. Can modify by modifying /.github/ISSUE_TEMPLATE/bug_issue.md.
See
https://help.github.com/articles/manually-creating-a-single-issue-template-for-your-repository/
for more information, strategy employed is #3.

.github/ISSUE_TEMPLATE/bug_issue.md

@@ -0,0 +1,40 @@
+---
+name: Bug Issue Template
+about: Bug reporting template
+title: '[BUG]'
+labels: 'bug'
+assignees: ''
+
+---
+
+<!---
+This is a suggested bug issue template for tedana.
+
+If there is other information that would be helpful to include, please don't hesitate to add it!
+-->
+
+<!-- 
+Summarize the bug in 2-3 sentences
+
+Update over time to include what additional discoveries have been made with respect to the bug
+-->
+### Summary
+
+<!-- 
+State functions or programs you suspect may be responsible if applicable
+-->
+### Suspected Cause
+
+<!--
+State the warning or error message if applicable
+-->
+### Warning/Error Message
+
+<!--
+If needed, place additional details below, such as OS, Python version/distribution, etc.
+-->
+### Additional
+
+<!--
+Don't forget to cross-reference other relevant issues via #
+-->