chore: Make sure we can build without credentials + readme nits (#72)

* chore: Make sure we can build without credentials + readme nits

* nit

Author: felipecsl

README.md

@@ -1,7 +1,7 @@
 # Eppo Android SDK
 
-[Eppo](https://www.geteppo.com) is a feature management and experimentation platform. This SDK enables feature flagging 
-and experimentation for customers of Eppo. An API key is required to use this SDK.
+[Eppo](https://geteppo.com) is a feature management and experimentation platform. This SDK enables
+feature flagging and experimentation for Eppo customers. An API key is required to use it.
 
 ## Usage
 
@@ -12,6 +12,7 @@ dependencies {
   implementation 'cloud.eppo:android-sdk:3.0.1'
 }
 ```
+Snapshots of the development version are available in [Sonatype's snapshots repository](https://s01.oss.sonatype.org/content/repositories/snapshots/).
 
 ## Getting Started
 For information on usage, refer to our [SDK Documentation](https://docs.geteppo.com/sdks/client-sdks/android/).

eppo/build.gradle

@@ -151,8 +151,8 @@ publishing {
             def snapshotsRepoUrl = "https://s01.oss.sonatype.org/content/repositories/snapshots/"
             url = version.endsWith('SNAPSHOT') ? snapshotsRepoUrl : releasesRepoUrl
             credentials {
-                username = ossrhUsername
-                password = ossrhPassword
+                username = project.properties.containsKey("ossrhUsername") ? project.properties["ossrhUsername"] : ""
+                password = project.properties.containsKey("ossrhPassword") ? project.properties["ossrhPassword"] : ""
             }
         }
     }