chore: remove tilde angular version at bower depdendency

Unable to find a suitable version for angular, please choose one:
    1) angular#1.2.16 which resolved to 1.2.16 and is required by famous-angular
    2) angular#1.2.18 which resolved to 1.2.18 and is required by angular-mocks#1.2.18

Set version to 1.2.18