Starting from scratch - pod install error

Following the Particule Documentation to start mobile application from scratch, I installed Cocoa gem, created a Xcode project, created a Pod file (with no extension) located at root folder of my project where my *.xcodeproj is located. From a Terminal prompt pointing to that directory, I call pod install but get the following error:

Minh-MacBook-Pro:ThermoAlert minh$ pwd
/Users/minh/documents/AppProjects/ThermoAlert
Minh-MacBook-Pro:ThermoAlert minh$ ls
Podfile ThermoAlert ThermoAlertTests
Pods ThermoAlert.xcodeproj ThermoAlertUITests
Minh-MacBook-Pro:ThermoAlert minh$ pod install
Analyzing dependencies
[!] The dependency SparkSetup is not used in any concrete target.
Minh-MacBook-Pro:ThermoAlert minh$

What am I missing?
Thanks for your help.

So I followed instruction from Cocoa guide instead.

And modified the content of my file Podfile with:

target 'ThermoAlert' do
pod 'SparkSetup'
end

Then, when trying to install the pod again:

Minh-MacBook-Pro:ThermoAlert minh$ pod install
Analyzing dependencies
Downloading dependencies
Using 1PasswordExtension (1.8.4)
Using AFNetworking (3.1.0)
Using Spark-SDK (0.5.1)
Using SparkSetup (0.6.1)
Generating Pods project
Integrating client project
Sending stats
Pod installation complete! There is 1 dependency from the Podfile and 4 total pods installed.
Minh-MacBook-Pro:ThermoAlert minh$

Hope this could help other newbies, and would be great if the the documentation gets updated or shows link to seen issues.