Add ci field: show how many installs were from a CI (#157)

Author: hugovk

README.md

@@ -296,6 +296,22 @@ Estimated cost: $0.01
 | Total          |           |         |             60 |
 ```
 
+Check how many downloads came from continuous integration servers:
+
+```console
+❯ pypinfo --percent --days 5 pillow ci
+Served from cache: False
+Data processed: 384.22 MiB
+Data billed: 385.00 MiB
+Estimated cost: $0.01
+
+| ci    | percent | download_count |
+| ----- | ------- | -------------- |
+| None  |  79.37% |     11,963,127 |
+| True  |  20.63% |      3,109,931 |
+| Total |         |     15,073,058 |
+```
+
 </details>
 
 ## Installation

pypinfo/cli.py

@@ -37,6 +37,7 @@
     OpenSSLVersion,
     Distro,
     DistroVersion,
+    CI,
     CPU,
     Libc,
     LibcVersion,
@@ -67,6 +68,7 @@
     'system-release': SystemRelease,
     'distro': Distro,
     'distro-version': DistroVersion,
+    'ci': CI,
     'cpu': CPU,
     'libc': Libc,
     'libc-version': LibcVersion,
@@ -121,7 +123,7 @@ def pypinfo(
     """Valid fields are:\n
     project | version | file | pyversion | percent3 | percent2 | impl | impl-version |\n
     openssl | date | month | year | country | installer | installer-version |\n
-    setuptools-version | system | system-release | distro | distro-version | cpu |\n
+    setuptools-version | system | system-release | distro | distro-version | ci | cpu |\n
     libc | libc-version
     """
     if auth:

pypinfo/fields.py

@@ -28,6 +28,7 @@
 SystemRelease = Field('system_release', 'details.system.release')
 Distro = Field('distro_name', 'details.distro.name')
 DistroVersion = Field('distro_version', 'details.distro.version')
+CI = Field('ci', 'details.ci')
 CPU = Field('cpu', 'details.cpu')
 Libc = Field('libc_name', 'details.distro.libc.lib')
 LibcVersion = Field('libc_version', 'details.distro.libc.version')