Merge pull request #147 from appodeal/release/3.8.1

Release/3.8.1: new arc + Appodeal SDK 3.8.1;

Merge pull request #131 from appodeal/release/3.3.3

Release/3.3.3

Merge pull request #123 from appodeal/release3.3.1

Release/3.3.1 (APDM-407)

Release v3.2.3

Beta release 3.2.2 (Appodeal SDK v3.2.1-beta.1)

Release v3.2.1 (Appodeal SDK 3.2.0)

Release v3.1.4

Beta release v3.1.3-beta.1

Release v3.0.2