feat: activity reports (#73)

* feat: scaffolding for activity report

* add tracing and instrumentation for debugging
* add top level activity report command
* id handling
* spawns a task to retrieve each user's activity report.
* Top-level framework for fetching data from GH

* feat: add structs for event structs

The event objects (not the webhook event objects) do not have the same
structure as the webhook event objects (sigh). So we have to go and
define all of these individually again.

* feat: fetch events and start simple report

Fetches events using pagination, and compiles the results into the
simplest of reports

* Lints

* add generic fetch_pages method

* use fetch_pages to fetch_events

* feat: add fetch events method to repo provider

* feat: add graphql query for org activity

The OrgActivity graph query seraches the given organisation for all
issue and PR events that were generated between two given dates.

A pagination object is also returned so that the full data set can be
returned.

The results can be used as a basis for generating a comprehensive
activity report

* fixup! make fields public

* feat: add query to API for activity

* feat: add organisation activity to cli

* feat: add activity reports

Parses an OrgActivity struct and generates code and engagement metrics
for each user.

* feat: aggregated report statistics

.cargo/config.toml

@@ -0,0 +1,2 @@
+[build]
+rustflags = ["--cfg", "tokio_unstable"]

.gitignore

@@ -8,4 +8,6 @@ github-api/swagger/rust
 github/swagger/*.jar
 github-api/swagger/.swagger-codegen-ignore
 
-**/node_modules
+**/node_modulesusers.txt
+users.txt
+/cli/org_activity.csv