diff --git a/README.md b/README.md
index 566f171..c6d7ca6 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,8 @@ Self-Update Mechanism for Go Commands using GitHub
 
 [go-github-selfupdate][] is a Go library to provide self-update mechanism to command line tools.
 
-Go does not provide the way to install/update the stable version of tools. By default, Go command line tools are updated
+Go does not provide the way to install/update the stable version of tools. By default, Go command line
+tools are updated:
 
 - using `go get -u` (updating to HEAD)
 - using system's package manager (depending on the platform)
@@ -18,8 +19,10 @@ By using this library, you will get 4th choice:
 
 - from your command line tool directly (and automatically)
 
-go-github-selfupdate detects the information of the latest release via [GitHub Releases API][] and check the current version.
-If newer version than itself is detected, it downloads released binary from GitHub and replaces itself.
+[go-github-selfupdate][] detects the information of the latest release via [GitHub Releases API][] and
+check the current version.
+If newer version than itself is detected, it downloads released binary from GitHub and replaces
+itself.
 
 - Automatically detects the latest version of released binary on GitHub
 - Retrieve the proper binary for the OS and arch where the binary is running
@@ -63,7 +66,8 @@ $ selfupdate-example -selfupdate
 
 It should replace itself and finally shows a message containing release notes.
 
-Please check the binary version is updated to `v1.2.4` with `-version`. The binary is up-to-date. So running `-selfupdate` again only shows 'Current binary is the latest version'.
+Please check the binary version is updated to `v1.2.4` with `-version`. The binary is up-to-date.
+So running `-selfupdate` again only shows 'Current binary is the latest version'.
 
 ### Real World Examples
 
@@ -282,9 +286,33 @@ In summary, structure of releases on GitHub looks like:
   - ... (Other binaries for v1.1.3)
 - ... (older versions)
 
-Tags which don't contain a version number are ignored (i.e. `nightly`). And releases marked as `pre-release` are also ignored.
+Tags which don't contain a version number are ignored (i.e. `nightly`). And releases marked
+as `pre-release` are also ignored.
 
-### Debugging
+### Development
+
+#### Running tests
+
+All library sources are put in `/selfupdate` directory. So you can run tests as following
+at the top of the repository:
+
+```
+$ go test -v ./selfupdate
+```
+
+Some tests are not run without setting a GitHub API token because they call GitHub API too many times.
+To run them, please generate an API token and set it to an environment variable.
+
+```
+$ export GITHUB_TOKEN="{token generated by you}"
+$ go test -v ./selfupdate
+```
+
+Above command run almost all tests and it's enough to check the behavior before creating a pull request.
+Some tests are still not tested because they depend on my personal API access token, though; for repositories
+on GitHub Enterprise or private repositories on GitHub.
+
+#### Debugging
 
 This library can output logs for debugging. By default, logger is disabled.
 You can enable the logger by following and can know the details of the self update.
@@ -293,6 +321,12 @@ You can enable the logger by following and can know the details of the self upda
 selfupdate.EnableLog()
 ```
 
+#### CI
+
+Tests run on CIs (Travis CI, Appveyor) are run with the token I generated. However, because of security
+reason, it is not used for the tests for pull requests. In the tests, a GitHub API token is not set and
+API rate limit is often exceeding. So please ignore the test failures on creating a pull request.
+
 ## Dependencies
 
 This library utilizes [go-github][] to retrieve the information of releases and [go-update][] to replace