Feature/#486 add gcc 7 to ci pipeline

Closes #486

With this merge request gcc 7.3.1 becomes available, which also causes an update from glm 0.9.8.5 to glm 0.9.9.0.

The drawback: glm changed quite a lot, e.g., a GLM_ENABLE_EXPERIMENTAL needs to be set if the glx-stuff is used, there are no default initializations of vector, matrix and quaternion types anymore, and - worse for us right now - there is an potentially uninitialized variable in the glm-code, causing an error in our code if we want to compare quaternions in our tests. Thus, we temporarily use an element-based quaternion comparison untill a new version of glm is available. For links providing more information on the aspects, I mentioned above, I refer the interested reader to our issue #486.

changed the description

By Fabian Lennartz on 2018-07-10T13:11:19 (imported from GitLab)

added 1 commit

• a2c60a25 - setting local_matrix_ by mat4 init instead of computations as proposed by jwendt

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By Andrea Bönsch on 2018-07-10T15:31:00 (imported from GitLab)

resolved all discussions

By Jonathan Ehret on 2018-07-11T09:11:00 (imported from GitLab)

added 1 commit

• f46a60fa - FIX: use identity quaternion [0,0,0,1] as default local_rotation

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By Andrea Bönsch on 2018-07-11T09:55:57 (imported from GitLab)

resolved all discussions

By Martin Bellgardt on 2018-07-11T10:46:38 (imported from GitLab)

resolved all discussions

By Martin Bellgardt on 2018-07-11T10:47:30 (imported from GitLab)

merged

By Fabian Lennartz on 2018-07-11T10:58:47 (imported from GitLab)

mentioned in commit c5ac0b06

By Fabian Lennartz on 2018-07-11T10:58:49 (imported from GitLab)